The production cross-section of high-mass $\tau$-lepton pairs is measured as a function of the dilepton visible invariant mass, using 140 fb$^{-1}$ of $\sqrt{s}=13$ TeV proton-proton collision data recorded with the ATLAS detector at the Large Hadron Collider. The measurement agrees with the predictions of the Standard Model. A fit to the invariant mass distribution is performed as a function of $b$-jet multiplicity, to constrain the non-resonant production of new particles described by an effective field theory or in models containing leptoquarks or $Z'$ bosons that couple preferentially to third-generation fermions. The constraints on new particles improve on previous results, and the constraints on effective operators include those affecting the anomalous magnetic moment of the $\tau$-lepton.
The measured unfolded differential cross sections.
The combined covariance matrix for the differential cross-section distribution.
Statistical covariance matrix for the differential cross-section distribution.
A search for cascade decays of charged sleptons and sneutrinos using final states characterized by three leptons (electrons or muons) and missing transverse momentum is presented. The analysis is based on a dataset with 140 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of $\sqrt{s}$=13 TeV recorded by the ATLAS detector at the Large Hadron Collider. This paper focuses on a supersymmetric scenario that is motivated by the muon anomalous magnetic moment observation, dark mattter relic density abundance, and electroweak naturalness. A mass spectrum involving light higgsinos and heavier sleptons with a bino at intermediate mass is targeted. No significant deviation from the Standard Model expectation is observed. This search enables to place stringent constraints on this model, excluding at the 95% confidence level charged slepton and sneutrino masses up to 450 GeV when assuming a lightest neutralino mass of 100 GeV and mass-degenerate selectrons, smuons and sneutrinos.
Distribution of $m_{3\ell}$ in SROS-on-$eee$. The SR selections are applied for each distribution, except for the variable shown, for which the selection is indicated by a black arrow. The last bin includes the overflow. The `Others' category contains the production of Higgs boson, 3-top, 4-top, and single-top processes. Distributions for SBH signals are overlaid. The bottom panels show the ratio of the observed data to the predicted total background yields. The hatched band includes all statistical and systematic uncertainties.
Distribution of $m_{3\ell}$ in SROS-on-$e\mu\mu$. The SR selections are applied for each distribution, except for the variable shown, for which the selection is indicated by a black arrow. The last bin includes the overflow. The `Others' category contains the production of Higgs boson, 3-top, 4-top, and single-top processes. Distributions for SBH signals are overlaid. The bottom panels show the ratio of the observed data to the predicted total background yields. The hatched band includes all statistical and systematic uncertainties.
Distribution of $E_{\text{T}}^{\text{miss}}$ in SROS-on-b-$eee$. The SR selections are applied for each distribution, except for the variable shown, for which the selection is indicated by a black arrow. The last bin includes the overflow. The `Others' category contains the production of Higgs boson, 3-top, 4-top, and single-top processes. Distributions for SBH signals are overlaid. The bottom panels show the ratio of the observed data to the predicted total background yields. The hatched band includes all statistical and systematic uncertainties.
This paper presents a first measurement of the cross-section for the charged-current Drell-Yan process $pp\rightarrow W^{\pm} \rightarrow \ell^{\pm} \nu$ above the resonance region, where $\ell$ is an electron or muon. The measurement is performed for transverse masses, $m_{\text{T}}^{\text{W}}$, between 200 GeV and 5000 GeV, using a sample of 140~fb$^{-1}$ of $pp$ collision data at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV collected by the ATLAS detector at the LHC during 2015-2018. The data are presented single differentially in transverse mass and double differentially in transverse mass and absolute lepton pseudorapidity. A test of lepton flavour universality shows no significant deviations from the Standard Model. The electron and muon channel measurements are combined to achieve a total experimental precision of 3% at low $m_{\text{T}}^{\text{W}}$. The single- and double differential $W$-boson charge asymmetries are evaluated from the measurements. A comparison to next-to-next-to-leading-order perturbative QCD predictions using several recent parton distribution functions and including next-to-leading-order electroweak effects indicates the potential of the data to constrain parton distribution functions. The data are also used to constrain four fermion operators in the Standard Model Effective Field Theory formalism, in particular the lepton-quark operator Wilson coefficient $c_{\ell q}^{(3)}.$
The expected EFT limits at 95% CL, shown for the linear-only electron, muon, and combined fits.
The expected EFT limits at 95% CL, shown for the linear+quadratic electron, muon, and combined fits.
The observed EFT limits at 95% CL, shown for the linear-only electron, muon, and combined fits.
The mass of the top quark is measured using top-antitop-quark pair events with high transverse momentum top quarks. The dataset, collected with the ATLAS detector in proton--proton collisions at $\sqrt{s}=13$ TeV delivered by the Large Hadron Collider, corresponds to an integrated luminosity of 140 fb$^{-1}$. The analysis targets events in the lepton-plus-jets decay channel, with an electron or muon from a semi-leptonically decaying top quark and a hadronically decaying top quark that is sufficiently energetic to be reconstructed as a single large-radius jet. The mean of the invariant mass of the reconstructed large-radius jet provides the sensitivity to the top quark mass and is simultaneously fitted with two additional observables to reduce the impact of the systematic uncertainties. The top quark mass is measured to be $m_t = 172.95 \pm 0.53$ GeV, which is the most precise ATLAS measurement from a single channel.
Values and uncertainties for the parameters of interest in the profile likelihood fit to $\overline{m_J}$, $m_{jj}$, and $m_{tj}$ using data. The parameters of interest are the top quark mass, $m_t$, and the ratio of the measured cross-section to the Standard Model expectation of the $t\bar{t}$ cross-section, $\mu$.
Post-fit central values and uncertaintes for the nuisance parameters (including MC stat uncertainty terms) used in the profile likelihood fit to $\overline{m_J}$, $m_{jj}$, and $m_{tj}$ using data.
Covariance matrix for the profile likelihood fit to $\overline{m_J}$, $m_{jj}$, and $m_{tj}$ using data.
This paper presents a search for massive, charged, long-lived particles with the ATLAS detector at the Large Hadron Collider using an integrated luminosity of 140 $fb^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV. These particles are expected to move significantly slower than the speed of light. In this paper, two signal regions provide complementary sensitivity. In one region, events are selected with at least one charged-particle track with high transverse momentum, large specific ionisation measured in the pixel detector, and time of flight to the hadronic calorimeter inconsistent with the speed of light. In the other region, events are selected with at least two tracks of opposite charge which both have a high transverse momentum and an anomalously large specific ionisation. The search is sensitive to particles with lifetimes greater than about 3 ns with masses ranging from 200 GeV to 3 TeV. The results are interpreted to set constraints on the supersymmetric pair production of long-lived R-hadrons, charginos and staus, with mass limits extending beyond those from previous searches in broad ranges of lifetime.
The contour for the excluded mass--lifetime region for stau pair production obtained with the di-track search. All masses and lifetimes shown that are below the curve and above 200 GeV are excluded by the observed data (while the expected exclusion is between the upper curve down to 210 GeV for lifetimes above 3000 ns). The sensitivity extends indefinitely to longer lifetimes.
The contour for the excluded mass--lifetime region for stau pair production obtained with the di-track search. All masses and lifetimes shown that are below the curve and above 200 GeV are excluded by the observed data (while the expected exclusion is between the upper curve down to 210 GeV for lifetimes above 3000 ns). The sensitivity extends indefinitely to longer lifetimes.
The contour for the excluded mass--lifetime region for stau pair production obtained with the di-track search. All masses and lifetimes shown that are below the curve and above 200 GeV are excluded by the observed data (while the expected exclusion is between the upper curve down to 210 GeV for lifetimes above 3000 ns). The sensitivity extends indefinitely to longer lifetimes.
Charged Higgs bosons produced either in top-quark decays or in association with a top-quark, subsequently decaying via $H^{\pm} \to \tau^{\pm}\nu_{\tau}$, are searched for in 140 $\text{fb}^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV recorded with the ATLAS detector. Depending on whether the top-quark produced together with the $H^{\pm}$ decays hadronically or semi-leptonically, the search targets $\tau$+jets or $\tau$+lepton final states, in both cases with a $\tau$-lepton decaying into a neutrino and hadrons. No significant excess over the Standard Model background expectation is observed. For the mass range of $80 \leq m_{H^{\pm}} \leq 3000$ GeV, upper limits at 95% confidence level are set on the production cross-section of the charged Higgs boson times the branching fraction $\mathrm{\cal{B}}(H^{\pm} \to \tau^{\pm}\nu_{\tau})$ in the range 4.5 pb-0.4 fb. In the mass range 80-160 GeV, assuming the Standard Model cross-section for $t\bar{t}$ production, this corresponds to upper limits between 0.27% and 0.02% on $\mathrm{\cal{B}}(t\to bH^{\pm}) \times \mathrm{\cal{B}}(H^{\pm} \to \tau^{\pm}\nu_{\tau})$.
Observed and expected 95 % CL exclusion limits on $\sigma(pp\to tbH^+)\times \mathrm{\cal{B}}(H^+ \to \tau \nu)$ as a function of $m_{H^{\pm}}$, from a combined fit in the $\tau$+jets and $\tau$+lepton channels. The surrounding shaded bands correspond to the 1$\sigma$ and 2$\sigma$ confidence intervals around the expected limit.
Observed and expected 95 % CL exclusion limits on $\mathrm{\cal{B}}(t\to bH^+)\times \mathrm{\cal{B}}(H^+ \to \tau \nu)$ as a function of $m_{H^{\pm}}$, from a combined fit in the $\tau$+jets and $\tau$+lepton channels. The surrounding shaded bands correspond to the 1$\sigma$ and 2$\sigma$ confidence intervals around the expected limit.
Observed and expected 95 % CL exclusion limits on $\tan\beta$ as a function of $m_{H^{\pm}}$, shown in the context of the hMSSM scenario, for $m_{H^{\pm}}>150$ GeV and $(1 \leq \tan\beta \leq 60)$. The surrounding shaded bands correspond to the 1$\sigma$ and 2$\sigma$ confidence intervals around the expected limit.
The production of $D^{\pm}$ and $D_{s}^{\pm}$ charmed mesons is measured using the $D^{\pm}/D_{s}^{\pm} \to ϕ(μμ)π^{\pm}$ decay channel with 137 fb$^{-1}$ of $\sqrt{s} = 13$ TeV proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider during the years 2016-2018. The charmed mesons are reconstructed in the range of transverse momentum $12 < p_\mathrm{T} < 100$ GeV and pseudorapidity $|η| < 2.5$. The differential cross-sections are measured as a function of transverse momentum and pseudorapidity, and compared with next-to-leading-order QCD predictions. The predictions are found to be consistent with the measurements in the visible kinematic region within the large theoretical uncertainties.
The measured differential cross-sections and the predictions from GM-VFNS and FONLL calculations for the $D^\pm$ meson in bins of $|\eta|$. The statistical, systematic (excluding branching ratio) and branching ratio uncertainties are shown separately for data, while the total theory uncertainties are shown for GM-VFNS and FONLL.
The measured differential cross-sections and the predictions from GM-VFNS and FONLL calculations for the $D^\pm$ meson in bins of $p_T$ for $|\eta| < 2.5$. The statistical, systematic (excluding branching ratio) and branching ratio uncertainties are shown separately for data, while the total theory uncertainties are shown for GM-VFNS and FONLL.
The measured differential cross-sections and the predictions from the GM-VFNS calculation for the $D_s^\pm$ meson in bins of $|\eta|$. The statistical, systematic (excluding branching ratio) and branching ratio uncertainties are shown separately for data, while the total theory uncertainties are shown for GM-VFNS.
This paper presents a new $τ$-lepton reconstruction and identification procedure at the ATLAS detector at the Large Hadron Collider, which leads to significantly improved performance in the case of physics processes where a highly boosted pair of $τ$-leptons is produced and one $τ$-lepton decays into a muon and two neutrinos ($τ_μ$), and the other decays into hadrons and one neutrino ($τ_{had}$). By removing the muon information from the signals used for reconstruction and identification of the $τ_{had}$ candidate in the boosted pair, the efficiency is raised to the level expected for an isolated $τ_{had}$. The new procedure is validated by selecting a sample of highly boosted $Z\rightarrowτ_μτ_{had}$ candidates from the data sample of $140$${fb}^{-1}$ of proton-proton collisions at $13$ TeV recorded with the ATLAS detector. Good agreement is found between data and simulation predictions in both the $Z\rightarrowτ_μτ_{had}$ signal region and in a background validation region. The results presented in this paper demonstrate the effectiveness of the $τ_{had}$ reconstruction with muon removal in enhancing the signal sensitivity of the boosted $τ_μτ_{had}$ channel at the ATLAS detector.
The distribution of the TauID jet RNN score for $\tau_\mathrm{had}^{\mu\mkern-10mu\backslash}$ in the SR. `$Z(\rightarrow\tau\tau)$+jets' represents the contributions from the signal process. `Top' represents the predicted contributions from the $t\bar{t}$, single-top-quark, and $tW$ processes. `Diboson' indicates the contributions from $WW$, $WZ$, and $ZZ$ processes. `Other' includes the contributions from the $Z(\rightarrow\ell\ell)$+jets, $W$+jets, and Higgs boson processes. The uncertainties shown include both statistical and systematic sources.
The distribution of the TauID jet RNN score for $\tau_\mathrm{had}^{\mu\mkern-10mu\backslash}$ in the VR. `$Z(\rightarrow\tau\tau)$+jets' represents the contributions from the signal process. `Top' represents the predicted contributions from the $t\bar{t}$, single-top-quark, and $tW$ processes. `Diboson' indicates the contributions from $WW$, $WZ$, and $ZZ$ processes. `Other' includes the contributions from the $Z(\rightarrow\ell\ell)$+jets, $W$+jets, and Higgs boson processes. The uncertainties shown include both statistical and systematic sources.
The distribution of the $p_\mathrm{T}{}_{\mu\mathrm{-had}}^\mathrm{col}$ in the SR. `$Z(\rightarrow\tau\tau)+\text{jets}$' represents the contributions from the signal process. `Diboson' indicates the contributions from $WW$, $WZ$, and $ZZ$ processes. `Top' represents the predicted contributions from the $t\bar{t}$, single-top-quark, and $tW$ processes. `Other' includes the contributions from the $Z(\rightarrow\ell\ell)$+jets, $W$+jets, and Higgs boson processes. The uncertainties shown include both statistical and systematic sources.
A search for exotic decays of the 125 GeV Higgs boson into a pair of new spin-0 particles, $H \to aa$, where one decays into a photon pair and the other into a $\tau$-lepton pair, is presented. Hadronic decays of the $\tau$-leptons are considered and reconstructed using a dedicated tagger for collimated $\tau$-lepton pairs. The search uses 140 fb$^{-1}$ of proton-proton collision data at a centre-of-mass energy of $\sqrt{s}=13$ TeV recorded between 2015 and 2018 by the ATLAS experiment at the Large Hadron Collider. The search is performed in the mass range of the $a$ boson between 10 GeV and 60 GeV. No significant excess of events is observed above the Standard Model background expectation. Model-independent upper limits at 95$\% $ confidence level are set on the branching ratio of the Higgs boson to the $\gamma\gamma\tau\tau$ final state, $\mathcal{B}(H\to aa\to \gamma\gamma\tau\tau)$, ranging from 0.2$\% $ to 2$\% $, depending on the $a$-boson mass hypothesis.
Distribution of the diphoton invariant mass for all events satisfying the analysis selections in the full Run 2 dataset.
Scan of the observed $p$-value as a function of $m_{a}$ for the background-only hypothesis.
The observed and expected ($\pm1\sigma$) upper limits at 95% CL on the branching ratio for $H\rightarrow aa\rightarrow \gamma\gamma\tau\tau$ as a function of the resonance mass hypothesis $m_{a}$.
A measurement of off-shell Higgs boson production in the $H^*\to ZZ\to 4\ell$ decay channel is presented. The measurement uses 140 fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV collected by the ATLAS detector at the Large Hadron Collider and supersedes the previous result in this decay channel using the same dataset. The data analysis is performed using a neural simulation-based inference method, which builds per-event likelihood ratios using neural networks. The observed (expected) off-shell Higgs boson production signal strength in the $ZZ\to 4\ell$ decay channel at 68% CL is $0.87^{+0.75}_{-0.54}$ ($1.00^{+1.04}_{-0.95}$). The evidence for off-shell Higgs boson production using the $ZZ\to 4\ell$ decay channel has an observed (expected) significance of $2.5\sigma$ ($1.3\sigma$). The expected result represents a significant improvement relative to that of the previous analysis of the same dataset, which obtained an expected significance of $0.5\sigma$. When combined with the most recent ATLAS measurement in the $ZZ\to 2\ell 2\nu$ decay channel, the evidence for off-shell Higgs boson production has an observed (expected) significance of $3.7\sigma$ ($2.4\sigma$). The off-shell measurements are combined with the measurement of on-shell Higgs boson production to obtain constraints on the Higgs boson total width. The observed (expected) value of the Higgs boson width at 68% CL is $4.3^{+2.7}_{-1.9}$ ($4.1^{+3.5}_{-3.4}$) MeV.
Values of the test statistic $t_{\mu_{\mathrm{off-shell}}}$ assuming a single parameter of interest $\mu_{\mathrm{off-shell}}$ obtained with an Asimov dataset and with data in the $H^*\rightarrow ZZ\rightarrow 4\ell$ decay channel. The values from the histogram-based analysis (Phys. Lett. B 846 (2023) 138223) are added for comparison. The 68% and 95% confidence intervals obtained from the Neyman construction are also added.
Values of the test statistic $t_{\mu_{\mathrm{off-shell}}}$ assuming a single parameter of interest $\mu_{\mathrm{off-shell}}$ obtained with an Asimov dataset and with data in the $H^*\rightarrow ZZ\rightarrow 4\ell$ decay channel. The values with all nuisance parameters fixed at their best-fit values (stat-only) are added for comparison. The 68% and 95% confidence intervals obtained from the Neyman construction are also added.
Values of the test statistic $t_{\mu_{\mathrm{off-shell}}}$ assuming a single parameter of interest $\mu_{\mathrm{off-shell}}$ obtained with an Asimov dataset and with data when combining the $H^*\rightarrow ZZ\rightarrow 4\ell$ and $H^*\rightarrow ZZ\rightarrow 2\ell 2\nu$ decay channels. The values with all nuisance parameters fixed at their best-fit values (stat-only) are added for comparison. The 68% and 95% confidence intervals obtained from the Neyman construction are also added.
A search for decays of the Higgs boson into a $Z$ boson and a light resonance, with a mass of 0.5-3.5 GeV, is performed using the full 140 fb$^{-1}$ dataset of 13 TeV proton-proton collisions recorded by the ATLAS detector during Run~2 of the LHC. Leptonic decays of the $Z$ boson and hadronic decays of the light resonance are considered. The resonance can be interpreted as a $J/\psi$ or $\eta_c$ meson, an axion-like particle, or a light pseudoscalar in two-Higgs-doublet models. Due to its low mass, it would be produced with high boost and reconstructed as a single small-radius jet of hadrons. A neural network is used to correct the Monte Carlo simulation of the background in a data-driven way. Two additional neural networks are used to distinguish signal from background. A binned profile-likelihood fit is performed on the final-state invariant mass distribution. No significant excess of events relative to the expected background is observed, and upper limits at 95% confidence level are set on the Higgs boson's branching fraction to a $Z$ boson and a light resonance. The exclusion limit is 10% for the lower masses, and increases for higher masses. Upper limits on the effective coupling $C^\text{eff}_{ZH}/\Lambda$ of an axion-like particle to a Higgs boson and $Z$ boson are also set at 95% confidence level, and range from 0.9 to 2 TeV$^{-1}$.
The angularity, for data, background (pre- and post-reweighting) and three $H\rightarrow Za$ signal hypotheses (for $a\rightarrow q\bar{q}/gg$ inclusively). Events are required to pass the complete event selection but not the classification NN requirement. The background normalization is set equal to that of the data for events passing the preselection and being in the $m_{\ell\ell j}$ 100-180 GeV region. The signal normalization assumes the SM Higgs boson inclusive production cross-section, $\mathcal{B}(H\to Za)=100\%$, and it is scaled up by a factor of 100. The error bars (hatched regions) represent the data (MC) sample's statistical uncertainty in the histograms and the ratio plots. Vertical arrows indicate data points that fall outside the displayed $y$-axis range.
The modified energy correlation function, for data, background (pre- and post-reweighting) and three $H\rightarrow Za$ signal hypotheses (for $a\rightarrow q\bar{q}/gg$ inclusively). Events are required to pass the complete event selection but not the classification NN requirement. The background normalization is set equal to that of the data for events passing the preselection and being in the $m_{\ell\ell j}$ 100-180 GeV region. The signal normalization assumes the SM Higgs boson inclusive production cross-section, $\mathcal{B}(H\to Za)=100\%$, and it is scaled up by a factor of 100. The error bars (hatched regions) represent the data (MC) sample's statistical uncertainty in the histograms and the ratio plots. Vertical arrows indicate data points that fall outside the displayed $y$-axis range.
$Z$ boson transverse momentum, for data, background (pre- and post-reweighting) and three $H\rightarrow Za$ signal hypotheses (for $a\rightarrow q\bar{q}/gg$ inclusively). Events are required to pass the complete event selection but not the classification NN requirement. The background normalization is set equal to that of the data for events passing the preselection and being in the $m_{\ell\ell j}$ 100-180 GeV region. The signal normalization assumes the SM Higgs boson inclusive production cross-section, $\mathcal{B}(H\to Za)=100\%$, and it is scaled up by a factor of 100. The error bars (hatched regions) represent the data (MC) sample's statistical uncertainty in the histograms and the ratio plots. Vertical arrows indicate data points that fall outside the displayed $y$-axis range.
A measurement of the $B^{0}$ meson lifetime and related properties using $B^0 \to J/ψK^{*0}$ decays in data from 13 TeV proton-proton collisions with an integrated luminosity of 140 fb$^{-1}$ recorded by the ATLAS detector at the LHC is presented. The measured effective lifetime is $$ τ= 1.5053 \pm 0.0012 ~\mathrm{(stat.)} \pm 0.0035 ~\mathrm{(syst.)~ps}. $$ The average decay width extracted from the effective lifetime, using parameters from external sources, is $$ Γ_d = 0.6639 \pm 0.0005 ~\mathrm{(stat.)} \pm 0.0016 ~\mathrm{(syst.)}\pm 0.0038 ~\textrm{(ext.)} \textrm{ ps}^{-1}, $$ where the uncertainties are statistical, systematic and from external sources. The earlier ATLAS measurement of $Γ_s$ in the $B^0_s \to J/ψϕ$ decay was used to derive a value for the ratio of the average decay widths $Γ_d$ and $Γ_s$ for $B^{0}$ and $B_s^{0}$ mesons respectively, of $$ \frac{Γ_d }{Γ_s } = 0.9905 \pm 0.0022 ~\textrm{(stat.)} \pm 0.0036 ~\textrm{(syst.)} \pm 0.0057 ~\textrm{(ext.)}. $$ The measured lifetime, average decay width and decay width ratio are in agreement with theoretical predictions and with measurements by other experiments. This measurement provides the most precise result of the effective lifetime of the $B^{0}$ meson to date.
The measured effective lifetime for the $B^0 \rightarrow J/\psi\,K^{*0}$ decay.
The measured average decay width $\Gamma_{d}\,$ extracted from the average lifetime.
The measured ratio $\Gamma_{d} / \Gamma_{s}\,$ of the average decay widths.
This article presents a search for a heavy charged Higgs boson produced in association with a top quark and a bottom quark, and decaying into a $W$ boson and a $125$ GeV Higgs boson $h$. The search is performed in final states with one charged lepton, missing transverse momentum, and jets using proton-proton collision data at $\sqrt{s} = 13$ TeV recorded with the ATLAS detector during Run 2 of the LHC at CERN. This data set corresponds to a total integrated luminosity of 140 fb$^{-1}$. The search is conducted by examining the reconstructed invariant mass distribution of the $Wh$ candidates for evidence of a localised excess in the charged Higgs boson mass range from $250$ GeV to $3$ TeV. No significant excess is observed and 95% confidence-level upper limits between $2.8$ pb and $1.2$ fb are placed on the production cross-section times branching ratio for charged Higgs bosons decaying into $Wh$.
Upper limit at the 95% CL on the product of the cross-section for the $pp \rightarrow tb H^{\pm}$ process and the branching ratio $B(W^{\pm} \times B (h \rightarrow b \bar{b} ))$ from the combined fit to all signal and control regions of the resolved analysis.
Upper limit at the 95% CL on the product of the cross-section for the $pp \rightarrow tb H^{\pm}$ process and the branching ratio $B(W^{\pm} \times B (h \rightarrow b \bar{b} ))$ from the combined fit to all signal and control regions of the merged analysis.
Product of acceptance and efficiency for pp->tbH(->Wh) as function of the charged Higgs boson mass for the resolved qqbb low-purity signal region.
A search for the production of three Higgs bosons ($HHH$) in the $b\bar{b}b\bar{b}b\bar{b}$ final state is presented. The search uses $126~\text{fb}^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV collected with the ATLAS detector at the Large Hadron Collider. The analysis targets both non-resonant and resonant production of $HHH$. The resonant interpretations primarily consider a cascade decay topology of $X\rightarrow SH\rightarrow HHH$ with masses of the new scalars $X$ and $S$ up to 1.5 TeV and 1 TeV, respectively. In addition to scenarios where $S$ is off-shell, the non-resonant interpretation includes a search for standard model (SM) $HHH$ production, with limits on the tri-linear and quartic Higgs self-coupling set. No evidence for $HHH$ production is observed. An upper limit of 59 fb is set, at 95% confidence level, on the cross-section for Standard-Model $HHH$ production.
Jet pairing efficiencies over the parameter space for the SM-like $(\kappa_3,\kappa_4)$ scan. The pairing efficiency is evaluated in the 6$b$ region when a correct pairing is possible — that is, the six leading jets are geometrically matched to truth-level b-quarks.
Jet pairing efficiencies over the parameter space for the TRSM signals. The pairing efficiency is evaluated in the 6$b$ region when a correct pairing is possible — that is, the six leading jets are geometrically matched to truth-level b-quarks.
Jet pairing efficiencies over the parameter space for the narrow-width heavy resonance signals. The pairing efficiency is evaluated in the 6$b$ region when a correct pairing is possible — that is, the six leading jets are geometrically matched to truth-level b-quarks.
The paper presents a search for supersymmetric particles produced in proton-proton collisions at $\sqrt{s}=$ 13 TeV and decaying into final states with missing transverse momentum and jets originating from charm quarks. The data were taken with the ATLAS detector at the Large Hadron Collider at CERN from 2015 to 2018 and correspond to an integrated luminosity of 139 fb$^{-1}$. No significant excess of events over the expected Standard Model background expectation is observed in optimized signal regions, and limits are set on the production cross-sections of the supersymmetric particles. Pair production of charm squarks or top squarks, each decaying into a charm quark and the lightest supersymmetric particle $\tilde{\chi}^0_1$, is excluded at 95% confidence level for squarks with masses up to 900 GeV for scenarios where the mass of $\tilde{\chi}^0_1$ is below 50 GeV. Additionally, the production of leptoquarks with masses up to 900 GeV is excluded for the scenario where up-type leptoquarks decay into a charm quark and a neutrino. Model-independent limits on cross-sections and event yields for processes beyond the Standard Model are also reported.
Summary of material in this HEPData record. <br/><br/> Truth Code snippets, SLHA files, Madgraph process cards and UFO files for the leptoquark models are available under "Additional Resources" (purple button on the left). <br/><br/> <b>Contours:</b> <ul> SUSY exclusion limits (best-expected SR combination) <ul> <a href="155678?version=1&table=Contour1">Expected</a> <a href="155678?version=1&table=Contour3">+1$\sigma$</a> <a href="155678?version=1&table=Contour2">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour4">Observed</a> <a href="155678?version=1&table=Contour5">+1$\sigma$</a> <a href="155678?version=1&table=Contour6">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (best-expected SR combination) as a function of $\Delta m(\tilde{t}_1,\tilde{\chi}_1^0)$ <ul> <a href="155678?version=1&table=Contour7">Expected</a> <a href="155678?version=1&table=Contour9">+1$\sigma$</a> <a href="155678?version=1&table=Contour8">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour10">Observed</a> <a href="155678?version=1&table=Contour11">+1$\sigma$</a> <a href="155678?version=1&table=Contour12">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-HM1) <ul> <a href="155678?version=1&table=Contour15">Expected</a> <a href="155678?version=1&table=Contour14">+1$\sigma$</a> <a href="155678?version=1&table=Contour13">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour18">Observed</a> <a href="155678?version=1&table=Contour16">+1$\sigma$</a> <a href="155678?version=1&table=Contour17">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-HM2) <ul> <a href="155678?version=1&table=Contour21">Expected</a> <a href="155678?version=1&table=Contour20">+1$\sigma$</a> <a href="155678?version=1&table=Contour19">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour24">Observed</a> <a href="155678?version=1&table=Contour22">+1$\sigma$</a> <a href="155678?version=1&table=Contour23">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-HM3) <ul> <a href="155678?version=1&table=Contour27">Expected</a> <a href="155678?version=1&table=Contour26">+1$\sigma$</a> <a href="155678?version=1&table=Contour25">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour30">Observed</a> <a href="155678?version=1&table=Contour28">+1$\sigma$</a> <a href="155678?version=1&table=Contour29">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-Comp1) <ul> <a href="155678?version=1&table=Contour33">Expected</a> <a href="155678?version=1&table=Contour32">+1$\sigma$</a> <a href="155678?version=1&table=Contour31">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour36">Observed</a> <a href="155678?version=1&table=Contour34">+1$\sigma$</a> <a href="155678?version=1&table=Contour35">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-Comp2) <ul> <a href="155678?version=1&table=Contour39">Expected</a> <a href="155678?version=1&table=Contour38">+1$\sigma$</a> <a href="155678?version=1&table=Contour37">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour42">Observed</a> <a href="155678?version=1&table=Contour40">+1$\sigma$</a> <a href="155678?version=1&table=Contour41">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-Comp3) <ul> <a href="155678?version=1&table=Contour45">Expected</a> <a href="155678?version=1&table=Contour44">+1$\sigma$</a> <a href="155678?version=1&table=Contour43">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour48">Observed</a> <a href="155678?version=1&table=Contour46">+1$\sigma$</a> <a href="155678?version=1&table=Contour47">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (SR-Comp-1c) <ul> <a href="155678?version=1&table=Contour50">Expected</a> <a href="155678?version=1&table=Contour49">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (scan over branching fraction for $m(\tilde{\chi}_1^0)=1$ GeV) <ul> <a href="155678?version=1&table=Contour51">Expected</a> <a href="155678?version=1&table=Contour53">+1$\sigma$</a> <a href="155678?version=1&table=Contour52">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour54">Observed</a> <a href="155678?version=1&table=Contour55">+1$\sigma$</a> <a href="155678?version=1&table=Contour56">-1$\sigma$</a> <br/> </ul> SUSY exclusion limits (scan over branching fraction for $m(\tilde{\chi}_1^0)=200$ GeV) <ul> <a href="155678?version=1&table=Contour57">Expected</a> <a href="155678?version=1&table=Contour59">+1$\sigma$</a> <a href="155678?version=1&table=Contour58">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour60">Observed</a> <a href="155678?version=1&table=Contour61">+1$\sigma$</a> <a href="155678?version=1&table=Contour62">-1$\sigma$</a> <br/> </ul> $\mathrm{LQ}^\mathrm{u}_{21}$ exclusion limits <ul> <a href="155678?version=1&table=Contour65">Expected</a> <a href="155678?version=1&table=Contour64">+1$\sigma$</a> <a href="155678?version=1&table=Contour63">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour68">Observed</a> <a href="155678?version=1&table=Contour66">+1$\sigma$</a> <a href="155678?version=1&table=Contour67">-1$\sigma$</a> <br/> </ul> $\mathrm{LQ}^\mathrm{u}_{22}$ exclusion limits <ul> <a href="155678?version=1&table=Contour71">Expected</a> <a href="155678?version=1&table=Contour70">+1$\sigma$</a> <a href="155678?version=1&table=Contour69">-1$\sigma$</a> <br/> <a href="155678?version=1&table=Contour74">Observed</a> <a href="155678?version=1&table=Contour72">+1$\sigma$</a> <a href="155678?version=1&table=Contour73">-1$\sigma$</a> <br/> </ul> </ul> <b>Cross-section upper limits:</b> <ul> SUSY signals (best-expected SR combination): <a href="155678?version=1&table=Cross-sectionupperlimit1">Observed</a> <br/> $\mathrm{LQ}^\mathrm{u}_{21}$ (combined High-Mass SRs): <a href="155678?version=1&table=Cross-sectionupperlimit2">Observed</a> <br/> $\mathrm{LQ}^\mathrm{u}_{22}$ (combined High-Mass SRs): <a href="155678?version=1&table=Cross-sectionupperlimit3">Observed</a> <br/> $U(1)$ pair (min) (combined High-Mass SRs): <a href="155678?version=1&table=Cross-sectionupperlimit6">Expected</a> <a href="155678?version=1&table=Cross-sectionupperlimit5">+1$\sigma$</a> <a href="155678?version=1&table=Cross-sectionupperlimit4">-1$\sigma$</a> <a href="155678?version=1&table=Cross-sectionupperlimit7">Observed</a> <br/> $U(1)$ pair (YM) (combined High-Mass SRs): <a href="155678?version=1&table=Cross-sectionupperlimit10">Expected</a> <a href="155678?version=1&table=Cross-sectionupperlimit9">+1$\sigma$</a> <a href="155678?version=1&table=Cross-sectionupperlimit8">-1$\sigma$</a> <a href="155678?version=1&table=Cross-sectionupperlimit11">Observed</a> <br/> </ul> <b>Signal region distributions:</b> <ul> <a href="155678?version=1&table=SRdistribution2">$E_\mathrm{T}^\mathrm{miss}$ Sig. in SR-HM1</a> <br/> <a href="155678?version=1&table=SRdistribution3">$m_\mathrm{T}^\mathrm{min}(c)$ in SR-HM2</a> <br/> <a href="155678?version=1&table=SRdistribution4">$R_\mathrm{ISR}$ in SR-Comp1</a> <br/> <a href="155678?version=1&table=SRdistribution5">$R_\mathrm{ISR}$ in SR-Comp2</a> <br/> <a href="155678?version=1&table=SRdistribution6">$R_\mathrm{ISR}$ in SR-Comp3</a> <br/> <a href="155678?version=1&table=SRdistribution1">$R_\mathrm{ISR}$ in SR-Comp-1c</a> <br/> </ul> <b>Acceptances:</b> <ul> SUSY signals: <a href="155678?version=1&table=Acceptance2">SR-HM1</a> <a href="155678?version=1&table=Acceptance3">SR-HM2</a> <a href="155678?version=1&table=Acceptance4">SR-HM3</a> <a href="155678?version=1&table=Acceptance5">SR-HM-Disc</a> <a href="155678?version=1&table=Acceptance6">SR-Comp1</a> <a href="155678?version=1&table=Acceptance7">SR-Comp2</a> <a href="155678?version=1&table=Acceptance8">SR-Comp3</a> <a href="155678?version=1&table=Acceptance1">SR-Comp-1c</a> <br/> $\mathrm{LQ}^\mathrm{u}_{21}$: <a href="155678?version=1&table=Acceptance9">SR-HM1</a> <a href="155678?version=1&table=Acceptance10">SR-HM2</a> <a href="155678?version=1&table=Acceptance11">SR-HM3</a> <a href="155678?version=1&table=Acceptance12">SR-HM-Disc</a> <br/> $\mathrm{LQ}^\mathrm{u}_{22}$: <a href="155678?version=1&table=Acceptance13">SR-HM1</a> <a href="155678?version=1&table=Acceptance14">SR-HM2</a> <a href="155678?version=1&table=Acceptance15">SR-HM3</a> <a href="155678?version=1&table=Acceptance16">SR-HM-Disc</a> <br/> $U(1)$ pair (min): <a href="155678?version=1&table=Acceptance17">SR-HM1</a> <a href="155678?version=1&table=Acceptance18">SR-HM2</a> <a href="155678?version=1&table=Acceptance19">SR-HM3</a> <a href="155678?version=1&table=Acceptance20">SR-HM-Disc</a> <br/> $U(1)$ pair (YM): <a href="155678?version=1&table=Acceptance21">SR-HM1</a> <a href="155678?version=1&table=Acceptance22">SR-HM2</a> <a href="155678?version=1&table=Acceptance23">SR-HM3</a> <a href="155678?version=1&table=Acceptance24">SR-HM-Disc</a> <br/> </ul> <b>Efficiencies:</b> <ul> $U(1)$ pair (min): <a href="155678?version=1&table=Efficiency1">SR-HM1</a> <a href="155678?version=1&table=Efficiency2">SR-HM2</a> <a href="155678?version=1&table=Efficiency3">SR-HM3</a> <a href="155678?version=1&table=Efficiency4">SR-HM-Disc</a> <br/> $U(1)$ pair (YM): <a href="155678?version=1&table=Efficiency5">SR-HM1</a> <a href="155678?version=1&table=Efficiency6">SR-HM2</a> <a href="155678?version=1&table=Efficiency7">SR-HM3</a> <a href="155678?version=1&table=Efficiency8">SR-HM-Disc</a> <br/> </ul> <b>Acceptance times efficiency:</b> <ul> SUSY signals: <a href="155678?version=1&table=Acceptancetimesefficiency2">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency3">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency4">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency5">SR-HM-Disc</a> <a href="155678?version=1&table=Acceptancetimesefficiency6">SR-Comp1</a> <a href="155678?version=1&table=Acceptancetimesefficiency7">SR-Comp2</a> <a href="155678?version=1&table=Acceptancetimesefficiency8">SR-Comp3</a> <a href="155678?version=1&table=Acceptancetimesefficiency1">SR-Comp-1c</a> <br/> $\mathrm{LQ}^\mathrm{u}_{21}$: <a href="155678?version=1&table=Acceptancetimesefficiency9">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency10">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency11">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency12">SR-HM-Disc</a> <br/> $\mathrm{LQ}^\mathrm{u}_{22}$: <a href="155678?version=1&table=Acceptancetimesefficiency13">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency14">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency15">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency16">SR-HM-Disc</a> <br/> $U(1)$ pair (min): <a href="155678?version=1&table=Acceptancetimesefficiency17">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency18">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency19">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency20">SR-HM-Disc</a> <br/> $U(1)$ pair (YM): <a href="155678?version=1&table=Acceptancetimesefficiency21">SR-HM1</a> <a href="155678?version=1&table=Acceptancetimesefficiency22">SR-HM2</a> <a href="155678?version=1&table=Acceptancetimesefficiency23">SR-HM3</a> <a href="155678?version=1&table=Acceptancetimesefficiency24">SR-HM-Disc</a> <br/> </ul> <b>Cutflow:</b> <ul> SUSY benchmarks: <a href="155678?version=1&table=Cutflow5">SR-HM1</a> <a href="155678?version=1&table=Cutflow6">SR-HM2</a> <a href="155678?version=1&table=Cutflow7">SR-HM3</a> <a href="155678?version=1&table=Cutflow8">SR-HM-Disc</a> <a href="155678?version=1&table=Cutflow2">SR-Comp1</a> <a href="155678?version=1&table=Cutflow3">SR-Comp2</a> <a href="155678?version=1&table=Cutflow4">SR-Comp3</a> <a href="155678?version=1&table=Cutflow1">SR-Comp-1c</a> <br/> LQ benchmarks: <a href="155678?version=1&table=Cutflow9">SR-HM1</a> <a href="155678?version=1&table=Cutflow10">SR-HM2</a> <a href="155678?version=1&table=Cutflow11">SR-HM3</a> <a href="155678?version=1&table=Cutflow12">SR-HM-Disc</a> <br/> </ul>
Expected exclusion limit at 95% CL for pair production of top squarks decaying to charm quarks and neutralinos.
Expected exclusion limit $(-1\sigma)$ at 95% CL for pair production of top squarks decaying to charm quarks and neutralinos.
A search is conducted for a new scalar boson $S$, with a mass distinct from that of the Higgs boson, decaying into four leptons ($\ell =$$e$, $\mu$) via an intermediate state containing two on-shell, promptly decaying new spin-1 bosons $Z_\text{d}$: $S \rightarrow Z_\text{d}Z_\text{d} \rightarrow 4\ell$, where the $Z_\text{d}$ boson has a mass between 15 and 300 GeV, and the $S$ boson has a mass between either 30 and 115 GeV or 130 and 800 GeV. The search uses proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider with an integrated luminosity of 139 fb$^{-1}$ at a centre-of-mass energy of $\sqrt{s}=13$ TeV. No significant excess above the Standard Model background expectation is observed. Upper limits at 95% confidence level are set on the production cross-section times branching ratio, $\sigma(gg \to S) \times \mathcal{B}(S\rightarrow Z_\text{d}Z_\text{d} \rightarrow 4\ell)$, as a function of the mass of both particles, $m_S$ and $m_{Z\text{d}}$.
Average dilepton mass distribution $\left\langle m_{\ell\ell}\right\rangle = \frac{1}{2}\left(m_{ab} + m_{cd}\right)$ in Signal Region 1.
Average dilepton mass distribution $\left\langle m_{\ell\ell}\right\rangle = \frac{1}{2}\left(m_{ab} + m_{cd}\right)$ in Signal Region 2.
Total invariant mass distribution $m_{4\ell}$ in Signal Region 1.
This paper reports a search for a light CP-odd scalar resonance with a mass of 20 GeV to 90 GeV in 13 TeV proton-proton collision data with an integrated luminosity of 140 fb$^{-1}$ collected with the ATLAS detector at the Large Hadron Collider. The analysis assumes the resonance is produced via gluon-gluon fusion and decays into a $\tau^{+}\tau^{-}$ pair which subsequently decays into a fully leptonic $\mu^{+}\nu_{\mu} \bar{\nu}_{\tau} e^{-} \bar{\nu}_{e} \nu_{\tau}$ or $e^{+}\nu_{e}\bar{\nu}_{\tau} \mu^-\bar{\nu}_{\mu}\nu_{\tau}$ final state. No significant excess of events above the predicted Standard Model background is observed. The results are interpreted within a flavour-aligned two-Higgs-doublet model, and a model-independent cross-section interpretation is also given. Upper limits at 95$%$ confidence level between 3.0 pb and 68 pb are set on the cross-section for producing a CP-odd Higgs boson that decays into a $\tau^+\tau^-$ pair.
Post-fit $m_\mathrm{MMC}$ distribution in the low-mass SR for the $m_A = 20\,\mathrm{GeV}$ signal mass hypothesis. $m_\mathrm{MMC}$ is the mass reconstructed by the Missing Mass Calculator. Processes contributing to the background Others are $Z/\gamma^* \rightarrow ee/\mu\mu$ and SM Higgs. The subscript on the $A\to\tau\tau$ process indicates the mass of the $A$ boson. Total includes all backgrounds and the signal process. The low-mass Signal Region is defined as: - 1 electron and 1 muon with opposite charge - $p_\mathrm{T}$ requirements of the leptons are a combination of the following: - $p_\mathrm{T}^e > 18\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 15\,\mathrm{GeV}$ - $p_\mathrm{T}^e > 10\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 25\,\mathrm{GeV}$ - $p_\mathrm{T}^e > 27\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 10\,\mathrm{GeV}$ - $\vert \eta_e \vert < 2.47$, excluding $1.37 < \vert \eta_e \vert < 1.52$ - $\vert \eta_\mu \vert < 2.7$ - no jets with $b$-quarks - $\Delta R_{\ell\ell} < 0.7$ - $E_\mathrm{T}^\mathrm{miss} > 50\,\mathrm{GeV}$ - $m_\mathrm{T}^\mathrm{tot} = \sqrt{\left(p_\mathrm{T}^e+p_\mathrm{T}^\mu+E_\mathrm{T}^\mathrm{miss}\right)^2-\left(\vec{p}_\mathrm{T}^{\,e}+\vec{p}_\mathrm{T}^{\,\mu}+\vec{E}_\mathrm{T}^{\,\mathrm{miss}}\right)^2} < 45\,\mathrm{GeV}$ - $m_\mathrm{MMC} > 0\,\mathrm{GeV}$
Post-fit $m_\mathrm{MMC}$ distribution in the low-mass SR for the $m_A = 20\,\mathrm{GeV}$ signal mass hypothesis. $m_\mathrm{MMC}$ is the mass reconstructed by the Missing Mass Calculator. Processes contributing to the background Others are $Z/\gamma^* \rightarrow ee/\mu\mu$ and SM Higgs. The subscript on the $A\to\tau\tau$ process indicates the mass of the $A$ boson. Total includes all backgrounds and the signal process. The low-mass Signal Region is defined as: - 1 electron and 1 muon with opposite charge - $p_\mathrm{T}$ requirements of the leptons are a combination of the following: - $p_\mathrm{T}^e > 18\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 15\,\mathrm{GeV}$ - $p_\mathrm{T}^e > 10\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 25\,\mathrm{GeV}$ - $p_\mathrm{T}^e > 27\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 10\,\mathrm{GeV}$ - $\vert \eta_e \vert < 2.47$, excluding $1.37 < \vert \eta_e \vert < 1.52$ - $\vert \eta_\mu \vert < 2.7$ - no jets with $b$-quarks - $\Delta R_{\ell\ell} < 0.7$ - $E_\mathrm{T}^\mathrm{miss} > 50\,\mathrm{GeV}$ - $m_\mathrm{T}^\mathrm{tot} = \sqrt{\left(p_\mathrm{T}^e+p_\mathrm{T}^\mu+E_\mathrm{T}^\mathrm{miss}\right)^2-\left(\vec{p}_\mathrm{T}^{\,e}+\vec{p}_\mathrm{T}^{\,\mu}+\vec{E}_\mathrm{T}^{\,\mathrm{miss}}\right)^2} < 45\,\mathrm{GeV}$ - $m_\mathrm{MMC} > 0\,\mathrm{GeV}$
Post-fit $m_\mathrm{MMC}$ distribution in the high-mass SR for the $m_A = 90\,\mathrm{GeV}$ signal mass hypothesis. $m_\mathrm{MMC}$ is the mass reconstructed by the Missing Mass Calculator. Processes contributing to the background Others are $Z/\gamma^* \rightarrow ee/\mu\mu$ and SM Higgs. The subscript on the $A\to\tau\tau$ process indicates the mass of the $A$ boson. otal includes all backgrounds and the signal process. The high-mass Signal Region is defined as: - 1 electron and 1 muon with opposite charge - $p_\mathrm{T}$ requirements of the leptons are a combination of the following: - $p_\mathrm{T}^e > 18\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 15\,\mathrm{GeV}$ or - $p_\mathrm{T}^e > 10\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 25\,\mathrm{GeV}$ or - $p_\mathrm{T}^e > 27\,\mathrm{GeV}$ and $p_\mathrm{T}^\mu > 10\,\mathrm{GeV}$ - $\vert \eta_e \vert < 2.47$, excluding $1.37 < \vert \eta_e \vert < 1.52$ - $\vert \eta_\mu \vert < 2.7$ - no jets with $b$-quarks - $\Delta R_{\ell\ell} < 1.0$ - $E_\mathrm{T}^\mathrm{miss} > 30\,\mathrm{GeV}$ - $m_\mathrm{T}^\mathrm{tot} = \sqrt{\left(p_\mathrm{T}^e+p_\mathrm{T}^\mu+E_\mathrm{T}^\mathrm{miss}\right)^2-\left(\vec{p}_\mathrm{T}^{\,e}+\vec{p}_\mathrm{T}^{\,\mu}+\vec{E}_\mathrm{T}^{\,\mathrm{miss}}\right)^2} < 65\,\mathrm{GeV}$ - $35\,\mathrm{GeV} < m_\mathrm{MMC} < 130\,\mathrm{GeV}$
This paper presents a search for supersymmetric particles in models with highly compressed mass spectra, in events consistent with being produced through vector boson fusion. The search uses 140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV collected by the ATLAS experiment at the Large Hadron Collider. Events containing at least two jets with a large gap in pseudorapidity, large missing transverse momentum, and no reconstructed leptons are selected. A boosted decision tree is used to separate events consistent with the production of supersymmetric particles from those due to Standard Model backgrounds. The data are found to be consistent with Standard Model predictions. The results are interpreted using simplified models of $R$-parity-conserving supersymmetry in which the lightest supersymmetric partner is a bino-like neutralino with a mass similar to that of the lightest chargino and second-to-lightest neutralino, both of which are wino-like. Lower limits at 95% confidence level on the masses of next-to-lightest supersymmetric partners in this simplified model are established between 117 and 120 GeV when the lightest supersymmetric partners are within 1 GeV in mass.
Observed and predicted background distributions of the BDT score in $\text{SR}_\text{2j}$ after the exclusion fit. The nominal, pre-fit prediction of an example benchmark signal with $(m(\widetilde{\chi}_{2}^{0}/\widetilde{\chi}_{1}^{\pm}), \widetilde{\chi}_{1}^{0}) = (100, 99)$ GeV is shown in red. The 'Other' category contains rare backgrounds from diboson, triboson and top-quark production processes. The hatched band represents the post-fit experimental, theoretical, and statistical uncertainties in the total background. The bottom panel of each plot shows the ratio between the data and the post-fit background prediction.
Observed and predicted background distributions of the BDT score in $\text{SR}_{\geq3\text{j}}$ after the exclusion fit. The nominal, pre-fit prediction of an example benchmark signal with $(m(\widetilde{\chi}_{2}^{0}/\widetilde{\chi}_{1}^{\pm}), \widetilde{\chi}_{1}^{0}) = (100, 99)$ GeV is shown in red. The 'Other' category contains rare backgrounds from diboson, triboson and top-quark production processes. The hatched band represents the post-fit experimental, theoretical, and statistical uncertainties in the total background. The bottom panel of each plot shows the ratio between the data and the post-fit background prediction.
Expected (dashed black line) and observed (solid red line) 95% CL exclusion limits on the compressed SUSY simplified model with a bino-like LSP and wino-like NLSPs being considered. These are shown with $\pm1\sigma_\text{exp}$ (yellow band) from experimental systematic and statistical uncertainties, and with $\pm1\sigma^{\text{SUSY}}_{\text{theory}}$ (red dotted lines) from signal cross-section uncertainties, respectively. The limits set by the ATLAS searches using the soft lepton signature is illustrated by the blue region while the limit imposed by the LEP experiments is shown in grey.
A search for the production of top-quark pairs with the same electric charge ($tt$ or $\bar{t}\bar{t}$) is presented. The analysis uses proton-proton collision data at $\sqrt{s}=13$ TeV, recorded by the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb$^{-1}$. Events with two same-charge leptons and at least two $b$-tagged jets are selected. Neural networks are employed to define two selections sensitive to additional couplings beyond the Standard Model that would enhance the production rate of same-sign top-quark pairs. No significant signal is observed, leading to an upper limit on the total production cross-section of same-sign top-quark pairs of 1.6 fb at 95$\%$ confidence level. Corresponding limits on the three Wilson coefficients associated with the ${\cal O}_{tu}^{(1)}$, ${\cal O}_{Qu}^{(1)}$, and ${\cal O}_{Qu}^{(8)}$ operators in the Standard Model Effective Field Theory framework are derived.
Distributions of the $\mathrm{NN^{SvsB}}$ output for data and the expected background after the likelihood fit in the $SR_{ctu ++}$ signal region. The post-fit background expectations are shown as filled histograms, the combined pre-fit background expectations are shown as dashed lines. The signal distribution using the Wilson coefficient values $c_{tu}^{(1)}=0.04$, $c_{Qu}^{(1)}=0.1$, $c_{Qu}^{(8)}=0.1$ is shown with a dotted line, normalized to the same number of events as the background.
Distributions of the $\mathrm{NN^{SvsB}}$ output for data and the expected background after the likelihood fit in the $SR_{ctu --}$ signal region. The post-fit background expectations are shown as filled histograms, the combined pre-fit background expectations are shown as dashed lines. The signal distribution using the Wilson coefficient values $c_{tu}^{(1)}=0.04$, $c_{Qu}^{(1)}=0.1$, $c_{Qu}^{(8)}=0.1$ is shown with a dotted line, normalized to the same number of events as the background.
Distributions of the $\mathrm{NN^{SvsB}}$ output for data and the expected background after the likelihood fit in the $SR_{cQu ++}$ signal region. The post-fit background expectations are shown as filled histograms, the combined pre-fit background expectations are shown as dashed lines. The signal distribution using the Wilson coefficient values $c_{tu}^{(1)}=0.04$, $c_{Qu}^{(1)}=0.1$, $c_{Qu}^{(8)}=0.1$ is shown with a dotted line, normalized to the same number of events as the background.
Inclusive cross-sections for top-quark pair production in association with charm quarks are measured with proton-proton collision data at a center-of-mass energy of 13 TeV corresponding to an integrated luminosity of 140 fb$^{-1}$, collected with the ATLAS experiment at the LHC between 2015 and 2018. The measurements are performed by requiring one or two charged leptons (electrons and muons), two $b$-tagged jets, and at least one additional jet in the final state. A custom flavor-tagging algorithm is employed for the simultaneous identification of $b$-jets and $c$-jets. In a fiducial phase space that replicates the acceptance of the ATLAS detector, the cross-sections for $t\bar{t}+ {\geq} 2c$ and $t\bar{t}+1c$ production are measured to be $1.28^{+0.27}_{-0.24}\;\text{pb}$ and $6.4^{+1.0}_{-0.9}\;\text{pb}$, respectively. The measurements are primarily limited by uncertainties in the modeling of inclusive $t\bar{t}$ and $t\bar{t}+b\bar{b}$ production, in the calibration of the flavor-tagging algorithm, and by data statistics. Cross-section predictions from various $t\bar{t}$ simulations are largely consistent with the measured cross-section values, though all underpredict the observed values by 0.5 to 2.0 standard deviations. In a phase-space volume without requirements on the $t\bar{t}$ decay products and the jet multiplicity, the cross-section ratios of $t\bar{t}+ {\geq} 2c$ and $t\bar{t}+1c$ to total $t\bar{t}+\text{jets}$ production are determined to be $(1.23 \pm 0.25) \%$ and $(8.8 \pm 1.3) \%$.
Measured cross-section values in the fiducial phase space and inclusive volume for the various $t\bar{t}+jets$ categories.
Post-fit agreement between data and MC prediction for $SR_{\mathrm{loose}}^{1\ell5j}$ signal region, which uses the invariant mass of the two geometrically closest c-tagged jets, $m_{\mathit{cc}}^{\mathrm{min}\Delta R}$, as an observable. The hatched uncertainty bands include all uncertainties and their correlations. The last bins contain overflow events. "Other Top" includes single-top-quark production and associated production of $t\bar{t}$ and single top quarks with bosons. "Non-Top" includes W+jets, Z+jets, and diboson processes.
Post-fit agreement between data and MC prediction for the $SR_{\mathrm{tight}}^{1\ell5j}$ signal region, which uses the invariant mass of the two geometrically closest jets tagged with c@11%, $m_{\mathit{cc}}^{\mathrm{min}\Delta R}$, as an observable. The hatched uncertainty bands include all uncertainties and their correlations. The last bins contain overflow events. "Other Top" includes single-top-quark production and associated production of $t\bar{t}$ and single top quarks with bosons. "Non-Top" includes W+jets, Z+jets, and diboson processes.
A search is presented for a heavy scalar ($H$) or pseudo-scalar ($A$) predicted by the two-Higgs-doublet models, where the $H/A$ is produced in association with a top-quark pair ($t\bar{t}H/A$), and with the $H/A$ decaying into a $t\bar{t}$ pair. Events are selected requiring exactly one or two opposite-charge electrons or muons. Data-driven corrections are applied to improve the modelling of the $t\bar{t}$+jets background in the regime with high jet and $b$-jet multiplicities. These include a novel multi-dimensional kinematic reweighting based on a neural network trained using data and simulations. An $H/A$-mass parameterised graph neural network is trained to optimise the signal-to-background discrimination. In combination with the previous search performed by the ATLAS Collaboration in the multilepton final state, the observed upper limits on the $t\bar{t}H/A \rightarrow t\bar{t}t\bar{t}$ production cross-section at 95% confidence level range between 14 fb and 5.0 fb for an $H/A$ with mass between 400 GeV and 1000 GeV, respectively. Assuming that both the $H$ and $A$ contribute to the $t\bar{t}t\bar{t}$ cross-section, $\tan\beta$ values below 1.7 or 0.7 are excluded for a mass of 400 GeV or 1000 GeV, respectively. The results are also used to constrain a model predicting the pair production of a colour-octet scalar, with the scalar decaying into a $t\bar{t}$ pair.
Post-fit distribution of the GNN score evaluated with $m_{H/A}$ = 400 GeV in the 1L region with $\geq 10$ jets and four $b$-tagged jets. The fit is performed under the background-only hypothesis.
Post-fit distribution of the GNN score evaluated with $m_{H/A}$ = 400 GeV in the 2LOS region with $\geq8$ jets and $\geq 4$ $𝑏$-tagged jets. The fit is performed under the background-only hypothesis.
Post-fit distribution of the GNN score evaluated with $m_{H/A}$ = 400 GeV in the validation region in the 1L region with $\geq 10$ jets. These regions do not enter the fit. The post-fit background prediction is obtained using the post-fit nuisance parameters from the background-only fit in the control and signal regions.
A combination of searches for the single production of vector-like top quarks ($T$) is presented. These analyses are based on proton$-$proton collisions at $\sqrt{s}=13$ TeV recorded in 2015$-$2018 with the ATLAS detector at the Large Hadron Collider, corresponding to an integrated luminosity of 139 fb$^{-1}$. The $T$-quark decay modes considered in this combination are into a top quark and either a Standard Model Higgs boson or a $Z$ boson ($T \to Ht$ and $T \to Zt$). The individual searches used in the combination are differentiated by the number of leptons ($e$, $\mu$) in the final state. The observed data are found to be in good agreement with the Standard Model background prediction. Interpretations are provided for a range of masses and couplings of the vector-like top quark for benchmark models and generalized representations in terms of 95% confidence level limits. For a benchmark signal prediction of a vector-like top quark SU2 singlet with electroweak coupling, $\kappa$, of 0.5, masses below 2.1 TeV are excluded, resulting in the most restrictive limits to date.
Observed and expected 95% CL upper limits on the total cross-section σ($pp$ → $T$ → $Ht/Zt$) as a function of $T$-quark mass in the SU(2) singlet representation assuming $\kappa$=0.3. The expected limits for the individual analyses are shown. The $HtZt$ analysis is only included in the limit calculation for $m_{\mathrm{T}}$ < 2.1 TeV.
Observed and expected 95% CL upper limits on the total cross-section σ($pp$ → $T$ → $Ht/Zt$) as a function of $T$-quark mass in the SU(2) singlet representation assuming $\kappa$=0.5. The expected limits for the individual analyses are shown. The $HtZt$ analysis is only included in the limit calculation for $m_{\mathrm{T}}$ < 2.1 TeV.
Observed and expected 95% CL upper limits on the total cross-section σ($pp$ → $T$ → $Ht/Zt$) as a function of $T$-quark mass in the SU(2) doublet representation assuming $\kappa$=0.3. The expected limits for the individual analyses are shown. The $HtZt$ analysis is only included in the limit calculation for $m_{\mathrm{T}}$ < 2.1 TeV.
A search for heavy right-handed Majorana neutrinos is performed with the ATLAS detector at the CERN Large Hadron Collider, using the 140 $\mathrm{fb}^{-1}$ of proton-proton collision data at $\sqrt{s}$ = 13 TeV collected during Run 2. This search targets $t\bar{t}$ production, in which both top quarks decay into a bottom quark and a $W$ boson, where one of the $W$ bosons decays hadronically and the other decays into an electron or muon and a heavy neutral lepton. The heavy neutral lepton is identified through a decay into an electron or muon and another $W$ boson, resulting in a pair of same-charge same-flavor leptons in the final state. This paper presents the first search for heavy neutral leptons in the mass range of 15-75 GeV using $t\bar{t}$ events. No significant excess is observed over the background expectation, and upper limits are placed on the signal cross-sections. Assuming a benchmark scenario of the phenomenological type-I seesaw model, these cross-section limits are then translated into upper limits on the mixing parameters of the heavy Majorana neutrino with Standard Model neutrinos.
Definitions of different signal and control regions. The control regions are enriched in events from the following processes. ttW, heavy-flavor (HF) fake, photon-conversion (PC), and charge-flip (CF). The 'Z veto' is defined as $m_{ee}$ not in [$m_Z$ - 10 GeV, $m_Z$ + 10 GeV].
Post-fit event yields for the different background processes in the signal regions, as obtained from the background-only fit in the high-mass region.
Expected and observed upper limits on the signal cross-sections at 95% CL.
Many extensions of the Standard Model, including those with dark matter particles, propose new mediator particles that decay into hadrons. This paper presents a search for such low mass narrow resonances decaying into hadrons using 140 fb$^{-1}$ of proton-proton collision data recorded with the ATLAS detector at a centre-of-mass energy of 13 TeV. The resonances are searched for in the invariant mass spectrum of large-radius jets with two-pronged substructure that are recoiling against an energetic photon from initial state radiation, which is used as a trigger to circumvent limitations on the maximum data recording rate. This technique enables the search for boosted hadronically decaying resonances in the mass range 20-100 GeV hitherto unprobed by the ATLAS Collaboration. The observed data are found to agree with Standard Model predictions and 95% confidence level upper limits are set on the coupling of a hypothetical new spin-1 $Z'$ resonance with Standard Model quarks as a function of the assumed $Z'$-boson mass in the range between 20 and 200 GeV.
Invariant mass $m_{J}$ of the resonance candidates in the region defined with central photon $\eta_{\gamma} < 1.3$ and a tagged large-$R$ jet after the fit to data under the background-only hypothesis. The total systematic uncertainty is shown as the hatched band. Three representative $Z^{`}$ signal distributions are overlaid as red lines. The signal is shown for $g_q=0.2$ with production cross sections of 309 fb, 143 fb, and 34.2 fb for $m_{Z^{`}}=(20,~50,~\text{and}~125~\text{GeV}$), respectively.
Invariant mass $m_{J}$ of the resonance candidates in the region defined with forward photon $\eta_{\gamma} > 1.3$ and a tagged large-$R$ jet after the fit to data under the background-only hypothesis. The total systematic uncertainty is shown as the hatched band. Three representative $Z^{`}$ signal distributions are overlaid as red lines. The signal is shown for $g_q=0.2$ with production cross sections of 309 fb, 143 fb, and 34.2 fb for $m_{Z^{`}}=(20,~50,~\text{and}~125~\text{GeV}$), respectively.
Invariant mass $m_{J}$ of the resonance candidates in the region defined with central photon $\eta_{\gamma} < 1.3$ and an anti-tagged large-$R$ jetafter the fit to data under the background-only hypothesis. The total systematic uncertainty is shown as the hatched band. Three representative $Z^{`}$ signal distributions are overlaid as red lines. The signal is shown for $g_q=0.2$ with production cross sections of 309 fb, 143 fb, and 34.2 fb for $m_{Z^{`}}=(20,~50,~\text{and}~125~\text{GeV}$), respectively.
Differential measurements of Higgs boson production in the $\tau$-lepton-pair decay channel are presented in the gluon fusion, vector-boson fusion (VBF), $VH$ and $t\bar{t}H$ associated production modes, with particular focus on the VBF production mode. The data used to perform the measurements correspond to 140 fb$^{-1}$ of proton-proton collisions collected by the ATLAS experiment at the LHC. Two methods are used to perform the measurements: the Simplified Template Cross-Section (STXS) approach and an Unfolded Fiducial Differential measurement considering only the VBF phase space. For the STXS measurement, events are categorized by their production mode and kinematic properties such as the Higgs boson's transverse momentum ($p^{\text{H}}_\text{T}$), the number of jets produced in association with the Higgs boson, or the invariant mass of the two leading jets ($m_{jj}$). For the VBF production mode, the ratio of the measured cross-section to the Standard Model prediction for $m_{jj}>1.5$ TeV and $p^{\text{H}}_\text{T}>200$ GeV ($p^{\text{H}}_\text{T}<200$ GeV) is ${1.29}^{+0.39}_{-0.34}$ (${0.12}^{+0.34}_{-0.33}$). This is the first VBF measurement for the higher-$p^{\text{H}}_\text{T}$ criteria, and the most precise for the lower-$p^{\text{H}}_\text{T}$ criteria. The fiducial cross-section measurements, which only consider the kinematic properties of the event, are performed as functions of variables characterizing the VBF topology, such as the signed $\Delta\phi_{jj}$ between the two leading jets. The measurements have a precision of 30%-50% and agree well with the Standard Model predictions. These results are interpreted in the SMEFT framework, and place the strongest constraints to date on the CP-odd Wilson coefficient $c_{H\tilde{W}}$.
Distribution of the reconstructed $\tau\tau$ invariant mass ($m_{\tau\tau}$) for all events in the VBF_0 signal region for $p_{\text{T}}^{H}<200$ GeV. The observed Higgs boson signal corresponds to $(\sigma\times B)/(\sigma\times B)_{\text{SM}}\,=\,0.99$. Entries with values above the $x$-axis range are shown in the last bin of each distribution. The prediction for each sample is determined from the likelihood fit performed to measure the total $pp\rightarrow H\rightarrow\tau\tau$ cross-section.
Distribution of the reconstructed $\tau\tau$ invariant mass ($m_{\tau\tau}$) for all events in the VBF_0 signal region for $p_{\text{T}}^{H}>200$ GeV. The observed Higgs boson signal corresponds to $(\sigma\times B)/(\sigma\times B)_{\text{SM}}\,=\,0.99$. Entries with values above the $x$-axis range are shown in the last bin of each distribution. The prediction for each sample is determined from the likelihood fit performed to measure the total $pp\rightarrow H\rightarrow\tau\tau$ cross-section.
Distribution of the reconstructed $\tau\tau$ invariant mass ($m_{\tau\tau}$) for all events in the VBF_1 signal region for $p_{\text{T}}^{H}<200$ GeV. The observed Higgs boson signal corresponds to $(\sigma\times B)/(\sigma\times B)_{\text{SM}}\,=\,0.99$. Entries with values above the $x$-axis range are shown in the last bin of each distribution. The prediction for each sample is determined from the likelihood fit performed to measure the total $pp\rightarrow H\rightarrow\tau\tau$ cross-section.
This paper presents measurements of top-antitop quark pair ($t\bar{t}$) production in association with additional $b$-jets. The analysis utilises 140 fb$^{-1}$ of proton-proton collision data collected with the ATLAS detector at the Large Hadron Collider at a centre-of-mass energy of 13 TeV. Fiducial cross-sections are extracted in a final state featuring one electron and one muon, with at least three or four $b$-jets. Results are presented at the particle level for both integrated cross-sections and normalised differential cross-sections, as functions of global event properties, jet kinematics, and $b$-jet pair properties. Observable quantities characterising $b$-jets originating from the top quark decay and additional $b$-jets are also measured at the particle level, after correcting for detector effects. The measured integrated fiducial cross-sections are consistent with $t\bar{t}b\bar{b}$ predictions from various next-to-leading-order matrix element calculations matched to a parton shower within the uncertainties of the predictions. State-of-the-art theoretical predictions are compared with the differential measurements; none of them simultaneously describes all observables. Differences between any two predictions are smaller than the measurement uncertainties for most observables.
- - - - - - - - Overview of HEPData Record - - - - - - - - <br/><br/> ATLAS public webpage of paper: <a href="https://atlas.web.cern.ch/Atlas/GROUPS/PHYSICS/PAPERS/TOPQ-2019-03/">link</a><br/><br/> <b>Fiducial phase space definitions:</b><br/> <i>Particle level:</i> <ul> <li> Common: N E = N MU = 1, CHARGE E != CHARGE MU <li> NJETS >= 2, NBJETS >= 2 <li> NJETS >= 3, NBJETS >= 3 <li> NJETS >= 4, NBJETS >= 3 <li> NJETS >= 4, NBJETS >= 4 <li> NJETS >= 5, NBJETS >= 4 </ul><br/> <b>Objects definitions:</b> <ul> <li> LEP PT > 28 GeV, ABS ETARAP LEP < 2.5 <li> JET PT > 25 GeV, ABS ETARAP JET < 2.5, R JET = 0.4 <li> BJET: >=1 b-hadron with PT > 5 GeV is associated to the jet via ghost matching </ul><br/> <b>Particle level:</b><br/> <br/>Data from Table 06: <a href="153521?table="Fiducial xsec results>Fiducial xsec results </a><br/><br/> <u>1D:</u><br/> Data bootstraps: <ul> <li> Data from Figure 09: <a href="153521?table=Bootstrap $N_{b-jets}$ in $≥2b$">Bootstrap $N_{b-jets}$ in $≥2b$ </a> <li> Data from Figure 10a: <a href="153521?table=Bootstrap $N_{b-jets}$ in $≥3b$">Bootstrap $N_{b-jets}$ in $≥3b$ </a> <li> Data from Figure 10b: <a href="153521?table=Bootstrap $N_{c/l-jets}$ in $≥3b$">Bootstrap $N_{c/l-jets}$ in $≥3b$ </a> <li> Data from Figure 10c: <a href="153521?table=Bootstrap $H_{T}^{had}$ in $≥3b$">Bootstrap $H_{T}^{had}$ in $≥3b$ </a> <li> Data from Figure 10d: <a href="153521?table=Bootstrap $\Delta R_{avg}^{bb}$ in $≥3b$">Bootstrap $\Delta R_{avg}^{bb}$ in $≥3b$ </a> <li> Data from Figure 11a: <a href="153521?table=Bootstrap $p_{T}(b_{1})$ in $≥3b$">Bootstrap $p_{T}(b_{1})$ in $≥3b$ </a> <li> Data from Figure 11b: <a href="153521?table=Bootstrap $p_{T}(b_{2})$ in $≥3b$">Bootstrap $p_{T}(b_{2})$ in $≥3b$ </a> <li> Data from Figure 11c: <a href="153521?table=Bootstrap $p_{T}(b_{1}^{top})$ in $≥3b$">Bootstrap $p_{T}(b_{1}^{top})$ in $≥3b$ </a> <li> Data from Figure 11d: <a href="153521?table=Bootstrap $p_{T}(b_{2}^{top})$ in $≥3b$">Bootstrap $p_{T}(b_{2}^{top})$ in $≥3b$ </a> <li> Data from Figure 12a: <a href="153521?table=Bootstrap $p_{T}(b_{3})$ in $≥3b$">Bootstrap $p_{T}(b_{3})$ in $≥3b$ </a> <li> Data from Figure 12b: <a href="153521?table=Bootstrap $p_{T}(b_{1}^{add})$ in $≥3b$">Bootstrap $p_{T}(b_{1}^{add})$ in $≥3b$ </a> <li> Data from Figure 13a: <a href="153521?table=Bootstrap $m(b_{1}b_{2})$ in $≥3b$">Bootstrap $m(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Figure 13b: <a href="153521?table=Bootstrap $p_{T}(b_{1}b_{2})$ in $≥3b$">Bootstrap $p_{T}(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Figure 13c: <a href="153521?table=Bootstrap $m(bb^{top})$ in $≥3b$">Bootstrap $m(bb^{top})$ in $≥3b$ </a> <li> Data from Figure 13d: <a href="153521?table=Bootstrap $p_{T}(bb^{top})$ in $≥3b$">Bootstrap $p_{T}(bb^{top})$ in $≥3b$ </a> <li> Data from Figure 14a: <a href="153521?table=Bootstrap $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$">Bootstrap $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$ </a> <li> Data from Figure 14b: <a href="153521?table=Bootstrap $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥3b≥1l/c$">Bootstrap $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥3b≥1l/c$ </a> <li> Data from Figure 14c: <a href="153521?table=Bootstrap $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$">Bootstrap $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$ </a> <li> Data from Figure 14d: <a href="153521?table=Bootstrap $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$">Bootstrap $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$ </a> <li> Data from Figure 15a: <a href="153521?table=Bootstrap $m(bb^{min\Delta R})$ in $≥4b$">Bootstrap $m(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Figure 15b: <a href="153521?table=Bootstrap $p_{T}(bb^{min\Delta R})$ in $≥4b$">Bootstrap $p_{T}(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Figure 15c: <a href="153521?table=Bootstrap $m(bb^{add})$ in $≥4b$">Bootstrap $m(bb^{add})$ in $≥4b$ </a> <li> Data from Figure 15d: <a href="153521?table=Bootstrap $p_{T}(bb^{add})$ in $≥4b$">Bootstrap $p_{T}(bb^{add})$ in $≥4b$ </a> <li> Data from Figure 01a (aux): <a href="153521?table=Bootstrap $|\eta(b_{3})|$ in $≥3b$">Bootstrap $|\eta(b_{3})|$ in $≥3b$ </a> <li> Data from Figure 01b (aux): <a href="153521?table=Bootstrap $|\eta(b_{1}^{add})|$ in $≥3b$">Bootstrap $|\eta(b_{1}^{add})|$ in $≥3b$ </a> <li> Data from Figure 02a (aux): <a href="153521?table=Bootstrap $\Delta R(b_{1}b_{2})$ in $≥3b$">Bootstrap $\Delta R(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Figure 02b (aux): <a href="153521?table=Bootstrap $m(e\mu bb^{top})$ in $≥3b$">Bootstrap $m(e\mu bb^{top})$ in $≥3b$ </a> <li> Data from Figure 03a (aux): <a href="153521?table=Bootstrap $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$">Bootstrap $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$ </a> <li> Data from Figure 03b (aux): <a href="153521?table=Bootstrap $\Delta\eta_{max}^{jj}$ in $≥3b$">Bootstrap $\Delta\eta_{max}^{jj}$ in $≥3b$ </a> <li> Data from Figure 04a (aux): <a href="153521?table=Bootstrap $H_{T}^{all}$ in $≥3b$">Bootstrap $H_{T}^{all}$ in $≥3b$ </a> <li> Data from Figure 04b (aux): <a href="153521?table=Bootstrap $m(e\mu b_{1}b_{2})$ in $≥3b$">Bootstrap $m(e\mu b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Figure 05a (aux): <a href="153521?table=Bootstrap $|\eta(b_{1})|$ in $≥3b$">Bootstrap $|\eta(b_{1})|$ in $≥3b$ </a> <li> Data from Figure 05b (aux): <a href="153521?table=Bootstrap $|\eta(b_{2})|$ in $≥3b$">Bootstrap $|\eta(b_{2})|$ in $≥3b$ </a> <li> Data from Figure 05c (aux): <a href="153521?table=Bootstrap $|\eta(b_{1}^{top})|$ in $≥3b$">Bootstrap $|\eta(b_{1}^{top})|$ in $≥3b$ </a> <li> Data from Figure 05d (aux): <a href="153521?table=Bootstrap $|\eta(b_{2}^{top})|$ in $≥3b$">Bootstrap $|\eta(b_{2}^{top})|$ in $≥3b$ </a> <li> Data from Figure 06a (aux): <a href="153521?table=Bootstrap $p_{T}(b_{1})$ in $≥4b$">Bootstrap $p_{T}(b_{1})$ in $≥4b$ </a> <li> Data from Figure 06b (aux): <a href="153521?table=Bootstrap $p_{T}(b_{2})$ in $≥4b$">Bootstrap $p_{T}(b_{2})$ in $≥4b$ </a> <li> Data from Figure 06c (axu): <a href="153521?table=Bootstrap $p_{T}(b_{1}^{top})$ in $≥4b$">Bootstrap $p_{T}(b_{1}^{top})$ in $≥4b$ </a> <li> Data from Figure 06d (aux): <a href="153521?table=Bootstrap $p_{T}(b_{2}^{top})$ in $≥4b$">Bootstrap $p_{T}(b_{2}^{top})$ in $≥4b$ </a> <li> Data from Figure 07a (aux): <a href="153521?table=Bootstrap $p_{T}(b_{3})$ in $≥4b$">Bootstrap $p_{T}(b_{3})$ in $≥4b$ </a> <li> Data from Figure 07b (aux): <a href="153521?table=Bootstrap $p_{T}(b_{4})$ in $≥4b$">Bootstrap $p_{T}(b_{4})$ in $≥4b$ </a> <li> Data from Figure 07c (aux): <a href="153521?table=Bootstrap $p_{T}(b_{1}^{add})$ in $≥4b$">Bootstrap $p_{T}(b_{1}^{add})$ in $≥4b$ </a> <li> Data from Figure 07d (aux): <a href="153521?table=Bootstrap $p_{T}(b_{2}^{add})$ in $≥4b$">Bootstrap $p_{T}(b_{2}^{add})$ in $≥4b$ </a> <li> Data from Figure 08a (aux): <a href="153521?table=Bootstrap $m(b_{1}b_{2})$ in $≥4b$">Bootstrap $m(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Figure 08b (aux): <a href="153521?table=Bootstrap $p_{T}(b_{1}b_{2})$ in $≥4b$">Bootstrap $p_{T}(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Figure 09a (aux): <a href="153521?table=Bootstrap $m(bb^{top})$ in $≥4b$">Bootstrap $m(bb^{top})$ in $≥4b$ </a> <li> Data from Figure 09b (aux): <a href="153521?table=Bootstrap $p_{T}(bb^{top})$ in $≥4b$">Bootstrap $p_{T}(bb^{top})$ in $≥4b$ </a> <li> Data from Figure 10a (aux): <a href="153521?table=Bootstrap $H_{T}^{all}$ in $≥4b$">Bootstrap $H_{T}^{all}$ in $≥4b$ </a> <li> Data from Figure 10b (aux): <a href="153521?table=Bootstrap $m(e\mu b_{1}b_{2})$ in $≥4b$">Bootstrap $m(e\mu b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Figure 11a (aux): <a href="153521?table=Bootstrap $m(e\mu bb^{top})$ in $≥4b$">Bootstrap $m(e\mu bb^{top})$ in $≥4b$ </a> <li> Data from Figure 11b (aux): <a href="153521?table=Bootstrap $H_{T}^{had}$ in $≥4b$">Bootstrap $H_{T}^{had}$ in $≥4b$ </a> <li> Data from Figure 11c (aux): <a href="153521?table=Bootstrap min$\Delta R(bb)$ in $≥4b$">Bootstrap min$\Delta R(bb)$ in $≥4b$ </a> <li> Data from Figure 11d (aux): <a href="153521?table=Bootstrap $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$">Bootstrap $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$ </a> <li> Data from Figure 12a (aux): <a href="153521?table=Bootstrap $\Delta R_{avg}^{bb}$ in $≥4b$">Bootstrap $\Delta R_{avg}^{bb}$ in $≥4b$ </a> <li> Data from Figure 12b (aux): <a href="153521?table=Bootstrap $\Delta\eta_{max}^{jj}$ in $≥4b$">Bootstrap $\Delta\eta_{max}^{jj}$ in $≥4b$ </a> <li> Data from Figure 12c (aux): <a href="153521?table=Bootstrap $N_{l/c-jets}$ in $≥4b$">Bootstrap $N_{l/c-jets}$ in $≥4b$ </a> <li> Data from Figure 13a (aux): <a href="153521?table=Bootstrap $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$">Bootstrap $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$ </a> <li> Data from Figure 13b (aux): <a href="153521?table=Bootstrap $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$">Bootstrap $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$ </a> <li> Data from Figure 13c (aux): <a href="153521?table=Bootstrap $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$">Bootstrap $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$ </a> <li> Data from Figure 13d (aux): <a href="153521?table=Bootstrap $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$">Bootstrap $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$ </a> <li> Data from Figure 14a (aux): <a href="153521?table=Bootstrap $|\eta(b_{1})|$ in $≥4b$">Bootstrap $|\eta(b_{1})|$ in $≥4b$ </a> <li> Data from Figure 14b (aux): <a href="153521?table=Bootstrap $|\eta(b_{2})|$ in $≥4b$">Bootstrap $|\eta(b_{2})|$ in $≥4b$ </a> <li> Data from Figure 14c (aux): <a href="153521?table=Bootstrap $|\eta(b_{1}^{top})|$ in $≥4b$">Bootstrap $|\eta(b_{1}^{top})|$ in $≥4b$ </a> <li> Data from Figure 14d (aux): <a href="153521?table=Bootstrap $|\eta(b_{2}^{top})|$ in $≥4b$">Bootstrap $|\eta(b_{2}^{top})|$ in $≥4b$ </a> <li> Data from Figure 15a (aux): <a href="153521?table=Bootstrap $|\eta(b_{3})|$ in $≥4b$">Bootstrap $|\eta(b_{3})|$ in $≥4b$ </a> <li> Data from Figure 15b (aux): <a href="153521?table=Bootstrap $|\eta(b_{4})|$ in $≥4b$">Bootstrap $|\eta(b_{4})|$ in $≥4b$ </a> <li> Data from Figure 15c (aux): <a href="153521?table=Bootstrap $|\eta(b_{1}^{add})|$ in $≥4b$">Bootstrap $|\eta(b_{1}^{add})|$ in $≥4b$ </a> <li> Data from Figure 15d (aux): <a href="153521?table=Bootstrap $|\eta(b_{2}^{add})|$ in $≥4b$">Bootstrap $|\eta(b_{2}^{add})|$ in $≥4b$ </a> </ul><br/> Measurements: <ul> <li> Data from Table 01 (aux): <a href="153521?table=Diff. XS $N_{b-jets}$ in $≥2b$">Diff. XS $N_{b-jets}$ in $≥2b$ </a> <li> Data from Table 02 (aux): <a href="153521?table=Diff. XS $H_{T}^{had}$ in $≥3b$">Diff. XS $H_{T}^{had}$ in $≥3b$ </a> <li> Data from Table 03 (aux): <a href="153521?table=Diff. XS $H_{T}^{all}$ in $≥3b$">Diff. XS $H_{T}^{all}$ in $≥3b$ </a> <li> Data from Table 04 (aux): <a href="153521?table=Diff. XS $\Delta R_{avg}^{bb}$ in $≥3b$">Diff. XS $\Delta R_{avg}^{bb}$ in $≥3b$ </a> <li> Data from Table 05 (aux): <a href="153521?table=Diff. XS $\Delta\eta_{max}^{jj}$ in $≥3b$">Diff. XS $\Delta\eta_{max}^{jj}$ in $≥3b$ </a> <li> Data from Table 06 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1})$ in $≥3b$">Diff. XS $p_{T}(b_{1})$ in $≥3b$ </a> <li> Data from Table 07 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}^{top})$ in $≥3b$">Diff. XS $p_{T}(b_{1}^{top})$ in $≥3b$ </a> <li> Data from Table 08 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2})$ in $≥3b$">Diff. XS $p_{T}(b_{2})$ in $≥3b$ </a> <li> Data from Table 09 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2}^{top})$ in $≥3b$">Diff. XS $p_{T}(b_{2}^{top})$ in $≥3b$ </a> <li> Data from Table 10 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{3})$ in $≥3b$">Diff. XS $p_{T}(b_{3})$ in $≥3b$ </a> <li> Data from Table 11 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}^{add})$ in $≥3b$">Diff. XS $p_{T}(b_{1}^{add})$ in $≥3b$ </a> <li> Data from Table 12 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1})|$ in $≥3b$">Diff. XS $|\eta(b_{1})|$ in $≥3b$ </a> <li> Data from Table 13 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1}^{top})|$ in $≥3b$">Diff. XS $|\eta(b_{1}^{top})|$ in $≥3b$ </a> <li> Data from Table 14 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2})|$ in $≥3b$">Diff. XS $|\eta(b_{2})|$ in $≥3b$ </a> <li> Data from Table 15 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2}^{top})|$ in $≥3b$">Diff. XS $|\eta(b_{2}^{top})|$ in $≥3b$ </a> <li> Data from Table 16 (aux): <a href="153521?table=Diff. XS $|\eta(b_{3})|$ in $≥3b$">Diff. XS $|\eta(b_{3})|$ in $≥3b$ </a> <li> Data from Table 17 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1}^{add})|$ in $≥3b$">Diff. XS $|\eta(b_{1}^{add})|$ in $≥3b$ </a> <li> Data from Table 18 (aux): <a href="153521?table=Diff. XS $m(b_{1}b_{2})$ in $≥3b$">Diff. XS $m(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 19 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}b_{2})$ in $≥3b$">Diff. XS $p_{T}(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 20 (aux): <a href="153521?table=Diff. XS $m(bb^{top})$ in $≥3b$">Diff. XS $m(bb^{top})$ in $≥3b$ </a> <li> Data from Table 21 (aux): <a href="153521?table=Diff. XS $p_{T}(bb^{top})$ in $≥3b$">Diff. XS $p_{T}(bb^{top})$ in $≥3b$ </a> <li> Data from Table 22 (aux): <a href="153521?table=Diff. XS $m(e\mu b_{1}b_{2})$ in $≥3b$">Diff. XS $m(e\mu b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 23 (aux): <a href="153521?table=Diff. XS $m(e\mu bb^{top})$ in $≥3b$">Diff. XS $m(e\mu bb^{top})$ in $≥3b$ </a> <li> Data from Table 24 (aux): <a href="153521?table=Diff. XS $\Delta R(b_{1}b_{2})$ in $≥3b$">Diff. XS $\Delta R(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 25 (aux): <a href="153521?table=Diff. XS $N_{l/c-jets}$ in $≥3b$">Diff. XS $N_{l/c-jets}$ in $≥3b$ </a> <li> Data from Table 26 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥3b$">Diff. XS $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥3b$ </a> <li> Data from Table 27 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$">Diff. XS $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$ </a> <li> Data from Table 28 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu bb^{top},l/c-jet)$ in $≥3b≥1l/c$">Diff. XS $\Delta R(e\mu bb^{top},l/c-jet)$ in $≥3b≥1l/c$ </a> <li> Data from Table 29 (aux): <a href="153521?table=Diff. XS $p_{T}(l/c-jet_{1}) - p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$">Diff. XS $p_{T}(l/c-jet_{1}) - p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$ </a> <li> Data from Table 30 (aux): <a href="153521?table=Diff. XS $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$">Diff. XS $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$ </a> <li> Data from Table 31 (aux): <a href="153521?table=Diff. XS $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$">Diff. XS $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$ </a> <li> Data from Table 32 (aux): <a href="153521?table=Diff. XS $H_{T}^{had}$ in $≥4b$">Diff. XS $H_{T}^{had}$ in $≥4b$ </a> <li> Data from Table 33 (aux): <a href="153521?table=Diff. XS $H_{T}^{all}$ in $≥4b$">Diff. XS $H_{T}^{all}$ in $≥4b$ </a> <li> Data from Table 34 (aux): <a href="153521?table=Diff. XS $\Delta R_{avg}^{bb}$ in $≥4b$">Diff. XS $\Delta R_{avg}^{bb}$ in $≥4b$ </a> <li> Data from Table 35 (aux): <a href="153521?table=Diff. XS $\Delta\eta_{max}^{jj}$ in $≥4b$">Diff. XS $\Delta\eta_{max}^{jj}$ in $≥4b$ </a> <li> Data from Table 36 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1})$ in $≥4b$">Diff. XS $p_{T}(b_{1})$ in $≥4b$ </a> <li> Data from Table 37 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}^{top})$ in $≥4b$">Diff. XS $p_{T}(b_{1}^{top})$ in $≥4b$ </a> <li> Data from Table 38 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2})$ in $≥4b$">Diff. XS $p_{T}(b_{2})$ in $≥4b$ </a> <li> Data from Table 39 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2}^{top})$ in $≥4b$">Diff. XS $p_{T}(b_{2}^{top})$ in $≥4b$ </a> <li> Data from Table 40 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{3})$ in $≥4b$">Diff. XS $p_{T}(b_{3})$ in $≥4b$ </a> <li> Data from Table 41 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}^{add})$ in $≥4b$">Diff. XS $p_{T}(b_{1}^{add})$ in $≥4b$ </a> <li> Data from Table 42 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{4})$ in $≥4b$">Diff. XS $p_{T}(b_{4})$ in $≥4b$ </a> <li> Data from Table 43 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{2}^{add})$ in $≥4b$">Diff. XS $p_{T}(b_{2}^{add})$ in $≥4b$ </a> <li> Data from Table 44 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1})|$ in $≥4b$">Diff. XS $|\eta(b_{1})|$ in $≥4b$ </a> <li> Data from Table 45 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1}^{top})|$ in $≥4b$">Diff. XS $|\eta(b_{1}^{top})|$ in $≥4b$ </a> <li> Data from Table 46 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2})|$ in $≥4b$">Diff. XS $|\eta(b_{2})|$ in $≥4b$ </a> <li> Data from Table 47 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2}^{top})|$ in $≥4b$">Diff. XS $|\eta(b_{2}^{top})|$ in $≥4b$ </a> <li> Data from Table 48 (aux): <a href="153521?table=Diff. XS $|\eta(b_{3})|$ in $≥4b$">Diff. XS $|\eta(b_{3})|$ in $≥4b$ </a> <li> Data from Table 49 (aux): <a href="153521?table=Diff. XS $|\eta(b_{1}^{add})|$ in $≥4b$">Diff. XS $|\eta(b_{1}^{add})|$ in $≥4b$ </a> <li> Data from Table 50 (aux): <a href="153521?table=Diff. XS $|\eta(b_{4})|$ in $≥4b$">Diff. XS $|\eta(b_{4})|$ in $≥4b$ </a> <li> Data from Table 51 (aux): <a href="153521?table=Diff. XS $|\eta(b_{2}^{add})|$ in $≥4b$">Diff. XS $|\eta(b_{2}^{add})|$ in $≥4b$ </a> <li> Data from Table 52 (aux): <a href="153521?table=Diff. XS $m(b_{1}b_{2})$ in $≥4b$">Diff. XS $m(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 53 (aux): <a href="153521?table=Diff. XS $p_{T}(b_{1}b_{2})$ in $≥4b$">Diff. XS $p_{T}(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 54 (aux): <a href="153521?table=Diff. XS $m(bb^{top})$ in $≥4b$">Diff. XS $m(bb^{top})$ in $≥4b$ </a> <li> Data from Table 55 (aux): <a href="153521?table=Diff. XS $p_{T}(bb^{top})$ in $≥4b$">Diff. XS $p_{T}(bb^{top})$ in $≥4b$ </a> <li> Data from Table 56 (aux): <a href="153521?table=Diff. XS $m(e\mu b_{1}b_{2})$ in $≥4b$">Diff. XS $m(e\mu b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 57 (aux): <a href="153521?table=Diff. XS $m(e\mu bb^{top})$ in $≥4b$">Diff. XS $m(e\mu bb^{top})$ in $≥4b$ </a> <li> Data from Table 58 (aux): <a href="153521?table=Diff. XS $m(bb^{min\Delta R})$ in $≥4b$">Diff. XS $m(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Table 59 (aux): <a href="153521?table=Diff. XS $p_{T}(bb^{min\Delta R})$ in $≥4b$">Diff. XS $p_{T}(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Table 60 (aux): <a href="153521?table=Diff. XS $m(bb^{add})$ in $≥4b$">Diff. XS $m(bb^{add})$ in $≥4b$ </a> <li> Data from Table 61 (aux): <a href="153521?table=Diff. XS $p_{T}(bb^{add})$ in $≥4b$">Diff. XS $p_{T}(bb^{add})$ in $≥4b$ </a> <li> Data from Table 62 (aux): <a href="153521?table=Diff. XS $min\Delta R(bb)$ in $≥4b$">Diff. XS $min\Delta R(bb)$ in $≥4b$ </a> <li> Data from Table 63 (aux): <a href="153521?table=Diff. XS $\Delta R(b_{1}b_{2})$ in $≥4b$">Diff. XS $\Delta R(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 64 (aux): <a href="153521?table=Diff. XS $N_{l/c-jets}$ in $≥4b$">Diff. XS $N_{l/c-jets}$ in $≥4b$ </a> <li> Data from Table 65 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥4b$">Diff. XS $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥4b$ </a> <li> Data from Table 66 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$">Diff. XS $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$ </a> <li> Data from Table 67 (aux): <a href="153521?table=Diff. XS $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$">Diff. XS $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$ </a> <li> Data from Table 68 (aux): <a href="153521?table=Diff. XS $p_{T}(l/c-jet_{1}) - p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$">Diff. XS $p_{T}(l/c-jet_{1}) - p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$ </a> <li> Data from Table 69 (aux): <a href="153521?table=Diff. XS $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$">Diff. XS $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$ </a> <li> Data from Table 70 (aux): <a href="153521?table=Diff. XS $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$">Diff. XS $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$ </a> </ul><br/> <u>2D:</u><br/> Correlation matrices: <ul> <li> Data from Table 71 (aux): <a href="153521?table=Corr. mtrx $N_{b-jets}$ in $≥2b$">Corr. mtrx $N_{b-jets}$ in $≥2b$ </a> <li> Data from Table 72 (aux): <a href="153521?table=Corr. mtrx $N_{b-jets}$ in $≥3b$">Corr. mtrx $N_{b-jets}$ in $≥3b$ </a> <li> Data from Table 73 (aux): <a href="153521?table=Corr. mtrx $H_{T}^{had}$ in $≥3b$">Corr. mtrx $H_{T}^{had}$ in $≥3b$ </a> <li> Data from Table 74 (aux): <a href="153521?table=Corr. mtrx $H_{T}^{all}$ in $≥3b$">Corr. mtrx $H_{T}^{all}$ in $≥3b$ </a> <li> Data from Table 75 (aux): <a href="153521?table=Corr. mtrx $\Delta R_{avg}^{bb}$ in $≥3b$">Corr. mtrx $\Delta R_{avg}^{bb}$ in $≥3b$ </a> <li> Data from Table 76 (aux): <a href="153521?table=Corr. mtrx $\Delta\eta_{max}^{jj}$ in $≥3b$">Corr. mtrx $\Delta\eta_{max}^{jj}$ in $≥3b$ </a> <li> Data from Table 77 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1})$ in $≥3b$">Corr. mtrx $p_{T}(b_{1})$ in $≥3b$ </a> <li> Data from Table 78 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}^{top})$ in $≥3b$">Corr. mtrx $p_{T}(b_{1}^{top})$ in $≥3b$ </a> <li> Data from Table 79 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2})$ in $≥3b$">Corr. mtrx $p_{T}(b_{2})$ in $≥3b$ </a> <li> Data from Table 80 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2}^{top})$ in $≥3b$">Corr. mtrx $p_{T}(b_{2}^{top})$ in $≥3b$ </a> <li> Data from Table 81 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{3})$ in $≥3b$">Corr. mtrx $p_{T}(b_{3})$ in $≥3b$ </a> <li> Data from Table 82 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}^{add})$ in $≥3b$">Corr. mtrx $p_{T}(b_{1}^{add})$ in $≥3b$ </a> <li> Data from Table 83 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1})|$ in $≥3b$">Corr. mtrx $|\eta(b_{1})|$ in $≥3b$ </a> <li> Data from Table 84 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1}^{top})|$ in $≥3b$">Corr. mtrx $|\eta(b_{1}^{top})|$ in $≥3b$ </a> <li> Data from Table 85 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2})|$ in $≥3b$">Corr. mtrx $|\eta(b_{2})|$ in $≥3b$ </a> <li> Data from Table 86 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2}^{top})|$ in $≥3b$">Corr. mtrx $|\eta(b_{2}^{top})|$ in $≥3b$ </a> <li> Data from Table 87 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{3})|$ in $≥3b$">Corr. mtrx $|\eta(b_{3})|$ in $≥3b$ </a> <li> Data from Table 88 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1}^{add})|$ in $≥3b$">Corr. mtrx $|\eta(b_{1}^{add})|$ in $≥3b$ </a> <li> Data from Table 89 (aux): <a href="153521?table=Corr. mtrx $m(b_{1}b_{2})$ in $≥3b$">Corr. mtrx $m(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 90 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}b_{2})$ in $≥3b$">Corr. mtrx $p_{T}(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 91 (aux): <a href="153521?table=Corr. mtrx $m(bb^{top})$ in $≥3b$">Corr. mtrx $m(bb^{top})$ in $≥3b$ </a> <li> Data from Table 92 (aux): <a href="153521?table=Corr. mtrx $p_{T}(bb^{top})$ in $≥3b$">Corr. mtrx $p_{T}(bb^{top})$ in $≥3b$ </a> <li> Data from Table 93 (aux): <a href="153521?table=Corr. mtrx $m(e\mu b_{1}b_{2})$ in $≥3b$">Corr. mtrx $m(e\mu b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 94 (aux): <a href="153521?table=Corr. mtrx $m(e\mu bb^{top})$ in $≥3b$">Corr. mtrx $m(e\mu bb^{top})$ in $≥3b$ </a> <li> Data from Table 95 (aux): <a href="153521?table=Corr. mtrx $\Delta R(b_{1}b_{2})$ in $≥3b$">Corr. mtrx $\Delta R(b_{1}b_{2})$ in $≥3b$ </a> <li> Data from Table 96 (aux): <a href="153521?table=Corr. mtrx $N_{l/c-jets}$ in $≥3b$">Corr. mtrx $N_{l/c-jets}$ in $≥3b$ </a> <li> Data from Table 97 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥3b$">Corr. mtrx $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥3b$ </a> <li> Data from Table 98 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$">Corr. mtrx $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥3b$ </a> <li> Data from Table 99 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu bb^{top},l/c-jet)$ in $≥3b≥1l/c$">Corr. mtrx $\Delta R(e\mu bb^{top},l/c-jet)$ in $≥3b≥1l/c$ </a> <li> Data from Table 100 (aux): <a href="153521?table=Corr. mtrx $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$">Corr. mtrx $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥3b≥1l/c$ </a> <li> Data from Table 101 (aux): <a href="153521?table=Corr. mtrx $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$">Corr. mtrx $|\eta(l/c-jet_{1})|$ in $≥3b≥1l/c$ </a> <li> Data from Table 102 (aux): <a href="153521?table=Corr. mtrx $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$">Corr. mtrx $p_{T}(l/c-jet_{1})$ in $≥3b≥1l/c$ </a> <li> Data from Table 103 (aux): <a href="153521?table=Corr. mtrx $H_{T}^{had}$ in $≥4b$">Corr. mtrx $H_{T}^{had}$ in $≥4b$ </a> <li> Data from Table 104 (aux): <a href="153521?table=Corr. mtrx $H_{T}^{all}$ in $≥4b$">Corr. mtrx $H_{T}^{all}$ in $≥4b$ </a> <li> Data from Table 105 (aux): <a href="153521?table=Corr. mtrx $\Delta R_{avg}^{bb}$ in $≥4b$">Corr. mtrx $\Delta R_{avg}^{bb}$ in $≥4b$ </a> <li> Data from Table 106 (aux): <a href="153521?table=Corr. mtrx $\Delta\eta_{max}^{jj}$ in $≥4b$">Corr. mtrx $\Delta\eta_{max}^{jj}$ in $≥4b$ </a> <li> Data from Table 107 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1})$ in $≥4b$">Corr. mtrx $p_{T}(b_{1})$ in $≥4b$ </a> <li> Data from Table 108 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}^{top})$ in $≥4b$">Corr. mtrx $p_{T}(b_{1}^{top})$ in $≥4b$ </a> <li> Data from Table 109 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2})$ in $≥4b$">Corr. mtrx $p_{T}(b_{2})$ in $≥4b$ </a> <li> Data from Table 110 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2}^{top})$ in $≥4b$">Corr. mtrx $p_{T}(b_{2}^{top})$ in $≥4b$ </a> <li> Data from Table 111 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{3})$ in $≥4b$">Corr. mtrx $p_{T}(b_{3})$ in $≥4b$ </a> <li> Data from Table 112 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}^{add})$ in $≥4b$">Corr. mtrx $p_{T}(b_{1}^{add})$ in $≥4b$ </a> <li> Data from Table 113 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{4})$ in $≥4b$">Corr. mtrx $p_{T}(b_{4})$ in $≥4b$ </a> <li> Data from Table 114 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{2}^{add})$ in $≥4b$">Corr. mtrx $p_{T}(b_{2}^{add})$ in $≥4b$ </a> <li> Data from Table 115 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1})|$ in $≥4b$">Corr. mtrx $|\eta(b_{1})|$ in $≥4b$ </a> <li> Data from Table 116 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1}^{top})|$ in $≥4b$">Corr. mtrx $|\eta(b_{1}^{top})|$ in $≥4b$ </a> <li> Data from Table 117 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2})|$ in $≥4b$">Corr. mtrx $|\eta(b_{2})|$ in $≥4b$ </a> <li> Data from Table 118 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2}^{top})|$ in $≥4b$">Corr. mtrx $|\eta(b_{2}^{top})|$ in $≥4b$ </a> <li> Data from Table 119 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{3})|$ in $≥4b$">Corr. mtrx $|\eta(b_{3})|$ in $≥4b$ </a> <li> Data from Table 120 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{1}^{add})|$ in $≥4b$">Corr. mtrx $|\eta(b_{1}^{add})|$ in $≥4b$ </a> <li> Data from Table 121 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{4})|$ in $≥4b$">Corr. mtrx $|\eta(b_{4})|$ in $≥4b$ </a> <li> Data from Table 122 (aux): <a href="153521?table=Corr. mtrx $|\eta(b_{2}^{add})|$ in $≥4b$">Corr. mtrx $|\eta(b_{2}^{add})|$ in $≥4b$ </a> <li> Data from Table 123 (aux): <a href="153521?table=Corr. mtrx $m(b_{1}b_{2})$ in $≥4b$">Corr. mtrx $m(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 124 (aux): <a href="153521?table=Corr. mtrx $p_{T}(b_{1}b_{2})$ in $≥4b$">Corr. mtrx $p_{T}(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 125 (aux): <a href="153521?table=Corr. mtrx $m(bb^{top})$ in $≥4b$">Corr. mtrx $m(bb^{top})$ in $≥4b$ </a> <li> Data from Table 126 (aux): <a href="153521?table=Corr. mtrx $p_{T}(bb^{top})$ in $≥4b$">Corr. mtrx $p_{T}(bb^{top})$ in $≥4b$ </a> <li> Data from Table 127 (aux): <a href="153521?table=Corr. mtrx $m(e\mu b_{1}b_{2})$ in $≥4b$">Corr. mtrx $m(e\mu b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 128 (aux): <a href="153521?table=Corr. mtrx $m(e\mu bb^{top})$ in $≥4b$">Corr. mtrx $m(e\mu bb^{top})$ in $≥4b$ </a> <li> Data from Table 129 (aux): <a href="153521?table=Corr. mtrx $m(bb^{min\Delta R})$ in $≥4b$">Corr. mtrx $m(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Table 130 (aux): <a href="153521?table=Corr. mtrx $p_{T}(bb^{min\Delta R})$ in $≥4b$">Corr. mtrx $p_{T}(bb^{min\Delta R})$ in $≥4b$ </a> <li> Data from Table 131 (aux): <a href="153521?table=Corr. mtrx $m(bb^{add})$ in $≥4b$">Corr. mtrx $m(bb^{add})$ in $≥4b$ </a> <li> Data from Table 132 (aux): <a href="153521?table=Corr. mtrx $p_{T}(bb^{add})$ in $≥4b$">Corr. mtrx $p_{T}(bb^{add})$ in $≥4b$ </a> <li> Data from Table 133 (aux): <a href="153521?table=Corr. mtrx min$\Delta R(bb)$ in $≥4b$">Corr. mtrx min$\Delta R(bb)$ in $≥4b$ </a> <li> Data from Table 134 (aux): <a href="153521?table=Corr. mtrx $\Delta R(b_{1}b_{2})$ in $≥4b$">Corr. mtrx $\Delta R(b_{1}b_{2})$ in $≥4b$ </a> <li> Data from Table 135 (aux): <a href="153521?table=Corr. mtrx $N_{l/c-jets}$ in $≥4b$">Corr. mtrx $N_{l/c-jets}$ in $≥4b$ </a> <li> Data from Table 136 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥4b$">Corr. mtrx $\Delta R(e\mu b_{1}b_{2},b_{3})$ in $≥4b$ </a> <li> Data from Table 137 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$">Corr. mtrx $\Delta R(e\mu bb^{top}, b_{1}^{add})$ in $≥4b$ </a> <li> Data from Table 138 (aux): <a href="153521?table=Corr. mtrx $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$">Corr. mtrx $\Delta R(e\mu bb^{top}, l/c-jet_{1})$ in $≥4b≥1l/c$ </a> <li> Data from Table 139 (aux): <a href="153521?table=Corr. mtrx $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$">Corr. mtrx $p_{T}(l/c-jet_{1})-p_{T}(b_{1}^{add})$ in $≥4b≥1l/c$ </a> <li> Data from Table 140 (aux): <a href="153521?table=Corr. mtrx $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$">Corr. mtrx $|\eta(l/c-jet_{1})|$ in $≥4b≥1l/c$ </a> <li> Data from Table 141 (aux): <a href="153521?table=Corr. mtrx $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$">Corr. mtrx $p_{T}(l/c-jet_{1})$ in $≥4b≥1l/c$ </a> </ul><br/>
Measured and predicted fiducial cross-section results for additional b-jet production in four phase-space regions. The dashes (–) indicate that the predictions are not available. The differences between the various MC generator predictions are smaller than the size of theoretical uncertainties (20%–50%, not presented here) in the predictions.
Data bootstraps post unfolding for the normalised differential cross-section in the phase space with at least two $b$-jets as a function of the number of $b$-jets compared with predictions. The replicas are obtained by reweighting each observed data event by a random integer generated according to Poisson statistics, using the BootstrapGenerator software package (https://gitlab.cern.ch/atlas-physics/sm/StandardModelTools_BootstrapGenerator/BootstrapGenerator), which implements a technique described in ATL-PHYS-PUB-2021-011 (https://cds.cern.ch/record/2759945). The ATLAS event number and run number of each event are used as seed to uniquely but reproducibly initialise the random number generator for each event. The last bin contains the overflow.
This Letter presents a constraint on the total width of the Higgs boson ($\Gamma_H$) using a combined measurement of on-shell Higgs boson production and the production of four top quarks, which involves contributions from off-shell Higgs boson-mediated processes. This method relies on the assumption that the tree-level Higgs-top Yukawa coupling strength is the same for on-shell and off-shell Higgs boson production processes, thereby avoiding any assumptions about the relationship between on-shell and off-shell gluon fusion Higgs production rates, which were central to previous measurements. The result is based on up to 140 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV collected with the ATLAS detector at the Large Hadron Collider. The observed (expected) 95% confidence level upper limit on $\Gamma_H$ is 450 MeV (75 MeV). Additionally, considering the constraint on the Higgs-top Yukawa coupling from loop-induced Higgs boson production and decay processes further yields an observed (expected) upper limit of 160 MeV (55 MeV).
The observed profile likelihood ratio, $-2ln \Lambda$, as a function of $\Gamma_H$.
The observed profile likelihood ratio, $-2ln \Lambda$, as a function of $\Gamma_H/\Gamma_H^{SM}$ and $\kappa_t$.
The observed profile likelihood ratio, $-2ln \Lambda$, as a function of $\Gamma_H/\Gamma_H^{SM}$.
A combination of searches for singly and doubly charged Higgs bosons, $H^{\pm}$ and $H^{\pm\pm}$, produced via vector-boson fusion is performed using 140 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of 13 TeV, collected with the ATLAS detector during Run 2 of the Large Hadron Collider. Searches targeting decays to massive vector bosons in leptonic final states (electrons or muons) are considered. New constraints are reported on the production cross-section times branching fraction for charged Higgs boson masses between 200 GeV and 3000 GeV. The results are interpreted in the context of the Georgi-Machacek model for which the most stringent constraints to date are set for the masses considered in the combination.
Post-fit $m_{\mathrm{WZ}}$ distribution in the signal region for the SM background-only hypothesis. Data are shown as black markers with vertical error bars representing the statistical uncertainty. Filled histograms show contributions of various SM processes, with the hatched band representing the total uncertainty. The line shows the prediction of the GM model for $\sin \theta_{\mathrm{H}} = 0.17$ and $m_{\mathrm{H_5}} = 375$ GeV, where the $\sin \theta_{\mathrm{H}}$ value corresponds to the expected $95\%$ CL limit for that $H_5$ mass.
Post-fit $m_{\mathrm{WZ}}$ distribution in the signal region for the SM background-only hypothesis. Data are shown as black markers with vertical error bars representing the statistical uncertainty. Filled histograms show contributions of various SM processes, with the hatched band representing the total uncertainty. The line shows the prediction of the GM model for $\sin \theta_{\mathrm{H}} = 0.17$ and $m_{\mathrm{H_5}} = 375$ GeV, where the $\sin \theta_{\mathrm{H}}$ value corresponds to the expected $95\%$ CL limit for that $H_5$ mass.
Post-fit $m_{\mathrm{T}}$ distribution in the signal region for the SM background-only hypothesis. Data are shown as black markers with vertical error bars representing the statistical uncertainty. Filled histograms show contributions of various SM processes, with the hatched band representing the total uncertainty. The line shows the prediction of the GM model for $\sin \theta_{\mathrm{H}} = 0.17$ and $m_{\mathrm{H_5}} = 375$ GeV, where the $\sin \theta_{\mathrm{H}}$ value corresponds to the expected $95\%$ CL limit for that $H_5$ mass.
A search for a light charged Higgs boson produced in decays of the top quark, $t \to H^\pm b$ with $H^\pm \to cs$, is presented. This search targets the production of top-quark pairs $t\bar{t} \to Wb H^\pm b$, with $W \to \ell\nu$ ($\ell = e, \mu$), resulting in a lepton-plus-jets final state characterised by an isolated electron or muon and at least four jets. The search exploits $b$-quark and $c$-quark identification techniques as well as multivariate methods to suppress the dominant $t\bar{t}$ background. The data analysed correspond to 140 $\text{fb}^{-1}$ of $pp$ collisions at $\sqrt{s} = 13$ TeV recorded with the ATLAS detector at the LHC between 2015 and 2018. Observed (expected) 95% confidence-level upper limits on the branching fraction $\mathscr{B}(t\to H^\pm b)$, assuming $\mathscr{B}(t\to Wb) + \mathscr{B}(t \to H^\pm (\to cs)b)=1.0$, are set between 0.066% (0.077%) and 3.6% (2.3%) for a charged Higgs boson with a mass between 60 GeV and 168 GeV.
Distributions of the dijet mass. The processes $t\bar{t}$(allHad), $tW$, Single top, $t\bar{t}H$, Other top, $W$ + jets, $Z$ + jets, and $VV$ listed are combined with the multijet background in the ‘Other’ category. The uncertainty band represents the combined statistical and systematic uncertainty of the prediction. Overlaid are the shapes for the $H^{\pm}_{80}$ and $H^{\pm}_{150}$ signal samples normalised to the total background prediction.
Data and background yields after the background-only fit of the BDT-score distribution for the $130\,$GeV signal mass BDT training. For comparison, the expected signal yield for $\mathscr{B}_{H^{\pm}}=1.0\%$ is added.
Observed (solid line) and expected (dotted line) upper limits on $\mathscr{B}_{H^{\pm}}$ for charged Higgs boson with masses between $60\,$GeV and $168\,$GeV, assuming $\mathscr{B}(t \to H^{\pm}(\to cs) b) = 1.0$. The $\pm 1 \sigma$ and $\pm 2 \sigma$ variations around the expected upper limit are indicated by the green and yellow bands, respectively.
This paper presents a search for exotic decays of the Higgs boson into a pair of new pseudoscalar particles, $H\rightarrow aa$, where one pseudoscalar decays into a $b$-quark pair and the other decays into a $\tau$-lepton pair, in the mass range $12\leq m_{a}\leq 60$ GeV. The analysis uses $pp$ collision data at $\sqrt{s} = 13$ TeV collected with the ATLAS detector at the LHC, corresponding to an integrated luminosity of 140 ${fb}^{-1}$. No significant excess above the Standard Model (SM) prediction is observed. Assuming the SM Higgs boson production cross-section, the search sets upper limits at 95% confidence level on the branching ratio of Higgs bosons decaying into $b\bar{b}\tau^+\tau^-$, $\mathcal{B}(H \rightarrow aa \rightarrow b\bar{b}\tau^+\tau^-)$, between 2.2% and 3.9% depending on the pseudoscalar mass.
Visible mass $m^{\mathrm{vis}}(\mu\tau_{\mathrm{had}})$ and distribution for signal and the expected background. In order to compare the shapes, the expected signal distribution is shown assuming ten times the production cross section of the Higgs boson and a 100% branching ratio to $b\bar{b}\tau^+\tau^-$. Overflow events are included in the last bins.
Sum of the transverse mass $\Sigma m_T$ distributions for signal and the expected background. Events with high $m^{\mathrm{vis}}(\mu\tau_{\mathrm{had}})$ and high $\Sigma m_T$ are included in the $t\bar{t}$ region. In order to compare the shapes, the expected signal distribution is shown assuming ten times the production cross section of the Higgs boson and a 100% branching ratio to $b\bar{b}\tau^+\tau^-$. Overflow events are included in the last bins.
The pNN input variable visible mass $m^{\mathrm{vis}}(\mu\tau_{\mathrm{had}})$ is shown in the SR with no cut on the pNN discriminant. The signal shape is normalized to the same integral as the total background prediction. Overflow events are included in the last bins.
This Letter presents results from a combination of searches for Higgs boson pair production using 126$-$140 fb$^{-1}$ of proton-proton collision data at $\sqrt{s}=13$ TeV recorded with the ATLAS detector. At 95% confidence level (CL), the upper limit on the production rate is 2.9 times the standard model (SM) prediction, with an expected limit of 2.4 assuming no Higgs boson pair production. Constraints on the Higgs boson self-coupling modifier $\kappa_{\lambda}=\lambda_{HHH}/\lambda_{HHH}^\mathrm{SM}$, and the quartic $HHVV$ coupling modifier $\kappa_{2V}=g_{HHVV}/g_{HHVV}^\mathrm{SM}$, are derived individually, fixing the other parameter to its SM value. The observed 95% CL intervals are $-1.2 < \kappa_{\lambda} < 7.2$ and $0.6 < \kappa_{2V} < 1.5$, respectively, while the expected intervals are $-1.6 < \kappa_{\lambda} < 7.2$ and $0.4 < \kappa_{2V} < 1.6$ in the SM case. Constraints obtained for several interaction parameters within Higgs effective field theory are the strongest to date, offering insights into potential deviations from SM predictions.
Observed and expected 95% CL upper limits on the signal strength for inclusive ggF HH and VBF HH production from the bb̄τ<sup>+</sup>τ<sup>-</sup>, bb̄γγ, bb̄bb̄, multilepton and bb̄ℓℓ+E<sub>T</sub><sup>miss</sup> decay channels, and their statistical combination. The predicted SM cross-section assumes m<sub>H</sub> = 125 GeV. The expected limit, along with its associated ±1σ and ±2σ bands, is calculated for the assumption of no HH production and with all NPs profiled to the observed data.
Expected value of the test statistic (-2ln$\Lambda$), as a function of the $\kappa_\lambda$ parameter for $b\bar{b}b\bar{b}$.
Expected value of the test statistic (-2ln$\Lambda$), as a function of the $\kappa_\lambda$ parameter for $b\bar{b}\tau\tau$.
Measurements of jet cross-section ratios between inclusive bins of jet multiplicity are performed in 140 fb$^{-1}$ of proton--proton collisions with $\sqrt{s}=13$ TeV center-of-mass energy, recorded with the ATLAS detector at CERN's Large Hadron Collider. Observables that are sensitive the energy-scale and angular distribution of radiation due to the strong interaction in the final state are measured double-differentially, in bins of jet multiplicity, and are unfolded to account for acceptance and detector-related effects. Additionally, the scalar sum of the two leading jets' transverse momenta is measured triple-differentially, in bins of the third jet's transverse momentum as well as bins of jet multiplicity. The measured distributions are used to construct ratios of the inclusive jet-multiplicity bins, which have been shown to be sensitive to the strong coupling $\alpha_{\textrm S}$ while being less sensitive than other observables to systematic uncertainties and parton distribution functions. The measured distributions are compared with state-of-the-art QCD calculations, including next-to-next-to-leading-order predictions. Studies leading to reduced jet energy scale uncertainties significantly improve the precision of this work, and are documented herein.
R32 for $H_{T2}$, 60 GeV < $p_{T,3}$
R32 for $H_{T2}$, 0.05 x $H_{T2} < $p_{T,3}$
R32 for $H_{T2}$, 0.1 x $H_{T2} < $p_{T,3}$
$Z$ boson events at the Large Hadron Collider can be selected with high purity and are sensitive to a diverse range of QCD phenomena. As a result, these events are often used to probe the nature of the strong force, improve Monte Carlo event generators, and search for deviations from Standard Model predictions. All previous measurements of $Z$ boson production characterize the event properties using a small number of observables and present the results as differential cross sections in predetermined bins. In this analysis, a machine learning method called OmniFold is used to produce a simultaneous measurement of twenty-four $Z$+jets observables using $139$ fb$^{-1}$ of proton-proton collisions at $\sqrt{s}=13$ TeV collected with the ATLAS detector. Unlike any previous fiducial differential cross-section measurement, this result is presented unbinned as a dataset of particle-level events, allowing for flexible re-use in a variety of contexts and for new observables to be constructed from the twenty-four measured observables.
Differential cross-section in bins of dimuon $p_\text{T}$. The actual measurement is unbinned and available with examples at <a href="https://gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024">gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024</a>
Differential cross-section in bins of dimuon rapidity. The actual measurement is unbinned and available with examples at <a href="https://gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024">gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024</a>
Differential cross-section in bins of leading muon $p_\mathrm{T]$. The actual measurement is unbinned and available with examples at <a href="https://gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024">gitlab.cern.ch/atlas-physics/public/sm-z-jets-omnifold-2024</a>
A search is presented for non-resonant Higgs boson pair production, targeting the $bbZZ$, 4$V$ ($V$ = $W$ or $Z$), $VV\tau\tau$, 4$\tau$, $\gamma\gamma VV$ and $\gamma\gamma\tau\tau$ decay channels. Events are categorised based on the multiplicity of light charged leptons (electrons or muons), hadronically decaying tau leptons, and photons. The search is based on a data sample of proton-proton collisions at $\sqrt{s}$ = 13 TeV recorded with the ATLAS detector during Run 2 of the Large Hadron Collider, corresponding to an integrated luminosity of 140 fb$^{-1}$. No evidence of the signal is found and the observed (expected) upper limit on the cross-section for non-resonant Higgs boson pair production is determined to be 17 (11) times the Standard Model predicted cross-section at 95% confidence level under the background-only hypothesis. The observed (expected) constraints on the $HHH$ coupling modifier, $\kappa_{\lambda}$, are determined to be $-6.2 < \kappa_{\lambda} < 11.6$ ($-4.5 < \kappa_{\lambda} < 9.6$) at 95% confidence level, assuming the Standard Model for the expected limits and that new physics would only affect $\kappa_{\lambda}$.
Number of ggF and VBF SM HH signal events satisfying the preselection requirements from the targeted HH decay modes and their acceptance into the different ML search channels.
Number of ggF and VBF SM HH signal events satisfying the preselection requirements from the targeted HH decay modes and their acceptance into the different $\gamma\gamma$+ML search channels.
Distribution of the BDT output score in the 4l+2b channel signal region.
Properties of the underlying-event in $pp$ interactions are investigated primarily via the strange hadrons $K_{S}^{0}$, $\Lambda$ and $\bar\Lambda$, as reconstructed using the ATLAS detector at the LHC in minimum-bias $pp$ collision data at $\sqrt{s} = 13$ TeV. The hadrons are reconstructed via the identification of the displaced two-particle vertices corresponding to the decay modes $K_{S}^{0}\rightarrow\pi^+\pi^-$, $\Lambda\rightarrow\pi^-p$ and $\bar\Lambda\rightarrow\pi^+\bar{p}$. These are used in the construction of underlying-event observables in azimuthal regions computed relative to the leading charged-particle jet in the event. None of the hadronisation and underlying-event physics models considered can describe the data over the full kinematic range considered. Events with a leading charged-particle jet in the range of $10 < p_T \leq 40$ GeV are studied using the number of prompt charged particles in the transverse region. The ratio $N(\Lambda + \bar\Lambda)/N(K_{S}^{0})$ as a function of the number of such charged particles varies only slightly over this range. This disagrees with the expectations of some of the considered Monte Carlo models.
Mean multiplicity of $K^{0}_{S}$ per unit $(\eta, \phi)$ in the away region vs. leading-jet $p_{T}$
Statistical covariance between bins of Table 1
Mean multiplicity of $K^{0}_{S}$ per unit $(\eta, \phi)$ in the towards region vs. leading-jet $p_{T}$
A search for the non-resonant production of Higgs boson pairs in the $HH\rightarrow b\bar{b}\tau^+\tau^-$ channel is performed using 140 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of $13$ TeV recorded by the ATLAS detector at the CERN Large Hadron Collider. The analysis strategy is optimised to probe anomalous values of the Higgs boson self-coupling modifier $\kappa_\lambda$ and of the quartic $HHVV$ ($V = W,Z$) coupling modifier $\kappa_{2V}$. No significant excess above the expected background from Standard Model processes is observed. An observed (expected) upper limit $\mu_{HH}<5.9$$(3.3)$ is set at 95% confidence-level on the Higgs boson pair production cross-section normalised to its Standard Model prediction. The coupling modifiers are constrained to an observed (expected) 95% confidence interval of $-3.1 < \kappa_\lambda < 9.0$ ($-2.5 < \kappa_\lambda < 9.3$) and $-0.5 < \kappa_{2V} < 2.7$ ($-0.2 < \kappa_{2V} < 2.4$), assuming all other Higgs boson couplings are fixed to the Standard Model prediction. The results are also interpreted in the context of effective field theories via constraints on anomalous Higgs boson couplings and Higgs boson pair production cross-sections assuming different kinematic benchmark scenarios.
Observed (filled circles) and expected (open circles) 95% CL upper limits on $\mu_{HH}$ from the fit of each individual channel and the combined fit in the background-only ($\mu_{HH} = 0$) hypothesis. The dashed lines indicate the expected 95% CL upper limits on $\mu_{HH}$ in the SM hypothesis ($\mu_{HH} = 1$). The inner and outer bands indicate the $\pm 1\sigma$ and $\pm 2\sigma$ variations, respectively, on the expected limit with respect to the background-only hypothesis due to statistical and systematic uncertainties.
Observed and expected 95% CL upper limits on $\mu_{HH}$, $\mu_{ggF}$ and $\mu_{VBF}$ from the individual SR likelihood fits as well as the combined results. The $\mu_{ggF}$ and $\mu_{VBF}$ limits are quoted both from the results of the simultaneous fit of both signal strengths (central column), and from independent fits for the individual production modes, assuming the other to be as predicted by the SM. The uncertainties quoted on the combined expected upper limits correspond to the 1σ uncertainty band.
Observed (solid line) value of $-2\ln\Lambda$ as a function of $\kappa_{\lambda}$ for the combined fit, when all other coupling modifiers are fixed to their SM predictions.
A search for the resonant production of a heavy scalar $X$ decaying into a Higgs boson and a new lighter scalar $S$, through the process $X \to S(\to bb) H(\to \gamma\gamma)$, where the two photons are consistent with the Higgs boson decay, is performed. The search is conducted using an integrated luminosity of 140 fb$^{-1}$ of proton-proton collision data at a centre-of-mass energy of 13 TeV recorded with the ATLAS detector at the Large Hadron Collider. The search is performed over the mass range 170 $\leq$$m_{X}$$\leq$ 1000 GeV and 15 $\leq$$m_{S}$$\leq$ 500 GeV. Parameterised neural networks are used to enhance the signal purity and to achieve continuous sensitivity in a domain of the ($m_{X}$, $m_{S}$) plane. No significant excess above the expected background is found and 95% CL upper limits are set on the cross section times branching ratio, ranging from 39 fb to 0.09 fb. The largest deviation from the background-only expectation occurs for ($m_{X}$, $m_{S}$) = (575, 200) GeV with a local (global) significance of 3.5 (2.0) standard deviations.
Number of events for the 2 b-jet process category obtained from a background-only fit to data in the signal region and sideband. In the signal region the yield in the most signal-like bin of the PNN distribution, parameterised to the signal point mass (mX, mS) = (250, 100) GeV, is also provided. The uncertainties are symmetrised around the central value. The uncertainty in the total background is calculated taking correlations between the individual contributions into account. For the single Higgs boson processes, 'Other' includes the following production modes: VBF, WH, tHq, and tHW.
Number of events for the 1 b-jet process category obtained from a background-only fit to data in the signal region and sideband. In the signal region the yield in the most signal-like bin of the PNN distribution, parameterised to the signal point mass (mX, mS) = (1000, 70) GeV, is also provided. The uncertainties are symmetrised around the central value. The uncertainty in the total background is calculated taking correlations between the individual contributions into account. For the single Higgs boson processes, 'Other' includes the following production modes: VBF, WH, tHq, and tHW.
Expected and observed 95% CL upper limits on the signal cross section times the branching ratio of X → SH → b b $\gamma \gamma$ shown in the (mX, mS) plane, for each evaluated point. The values of the expected limit one and two standard deviations from the nominal value are also shown. The band at mS = 125 GeV is not included as these signal points are equivalent to those already probed in Phys. Rev. D 106 (2022) 052001.
A search is presented for flavour-changing neutral-current interactions involving the top quark, the Higgs boson and an up-type quark ($q=u,c$) with the ATLAS detector at the Large Hadron Collider. The analysis considers leptonic decays of the top quark along with Higgs boson decays into two $W$ bosons, two $Z$ bosons or a $\tau^{+}\tau^{-}$ pair. It focuses on final states containing either two leptons (electrons or muons) of the same charge or three leptons. The considered processes are $t\bar{t}$ and $Ht$ production. For the $t\bar{t}$ production, one top quark decays via $t\to Hq$. The proton-proton collision data set analysed amounts to 140 fb$^{-1}$ at $\sqrt{s}=13$ TeV. No significant excess beyond Standard Model expectations is observed and upper limits are set on the $t\to Hq$ branching ratios at 95% confidence level, amounting to observed (expected) limits of $\mathcal{B}(t\to Hu)<2.8\,(3.0) \times 10^{-4}$ and $\mathcal{B}(t\to Hc)<3.3\,(3.8) \times 10^{-4}$. Combining this search with other searches for $tHq$ flavour-changing neutral-current interactions previously conducted by ATLAS, considering $H\to b\bar{b}$ and $H\to\gamma\gamma$ decays, as well as $H\to\tau^{+}\tau^{-}$ decays with one or two hadronically decaying $\tau$-leptons, yields observed (expected) upper limits on the branching ratios of $\mathcal{B}(t\to Hu)<2.6\,(1.8) \times 10^{-4}$ and $\mathcal{B}(t\to Hc)<3.4\,(2.3) \times 10^{-4}$.
Pre-fit background composition of the SR$2\ell$ Dec. The table shows the event yields as opposed to just the percentages of the relevant background processes.
Pre-fit background composition of the SR$2\ell$ Prod. The table shows the event yields as opposed to just the percentages of the relevant background processes.
Pre-fit background composition of the SR$3\ell$ Dec. The table shows the event yields as opposed to just the percentages of the relevant background processes.
A search is presented for the pair production of higgsinos $\tilde{\chi}$ in gauge-mediated supersymmetry models, where the lightest neutralinos $\tilde{\chi}_1^0$ decay into a light gravitino $\tilde{G}$ in association with either a Higgs $h$ or a $Z$ boson. The search is performed with the ATLAS detector at the Large Hadron Collider using 139 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of $\sqrt{s}$ = 13 TeV. It targets final states in which a Higgs boson decays into a photon pair, while the other Higgs or $Z$ boson decays into a $b\bar{b}$ pair, with missing transverse momentum associated with the two gravitinos. Search regions dependent on the amount of missing transverse momentum are defined by the requirements that the diphoton mass should be consistent with the mass of the Higgs boson, and the $b\bar{b}$ mass with the mass of the Higgs or $Z$ boson. The main backgrounds are estimated with data-driven methods using the sidebands of the diphoton mass distribution. No excesses beyond Standard Model expectations are observed and higgsinos with masses up to 320 GeV are excluded, assuming a branching fraction of 100% for $\tilde{\chi}_1^0\rightarrow h\tilde{G}$. This analysis excludes higgsinos with masses of 130 GeV for branching fractions to $h\tilde{G}$ as low as 36%, thus providing complementarity to previous ATLAS searches in final states with multiple leptons or multiple $b$-jets, targeting different decays of the electroweak bosons.
<b>- - - - - - - - Overview of HEPData Record - - - - - - - -</b> <b>Histograms:</b><ul> <li><a href=?table=Distribution1>Figure 3a: $m_{\gamma\gamma}$ Distribution in VR1</a> <li><a href=?table=Distribution2>Figure 3b: $E_{\mathrm{T}}^{\mathrm{miss}}$ Distribution in VR1</a> <li><a href=?table=Distribution3>Figure 3c: $m_{\gamma\gamma}$ Distribution in VR2</a> <li><a href=?table=Distribution4>Figure 3d: $E_{\mathrm{T}}^{\mathrm{miss}}$ Distribution in VR2</a> <li><a href=?table=Distribution5>Figure 4a: N-1 $m_{\gamma\gamma}$ Distribution for SR1h</a> <li><a href=?table=Distribution6>Figure 4b: N-1 $m_{\gamma\gamma}$ Distribution for SR1Z</a> <li><a href=?table=Distribution7>Figure 4c: N-1 $m_{\gamma\gamma}$ Distribution for SR2</a> <li><a href=?table=Distribution8>Auxiliary Figure 1: Signal and Validation Region Yields</a> </ul> <b>Tables:</b><ul> <li><a href=?table=YieldsTable1>Table 3: Signal Region Yields & Model-independent Limits</a> <li><a href=?table=Cutflow1>Auxiliary Table 1: Benchmark Signal Cutflows</a> </ul> <b>Cross section limits:</b><ul> <li><a href=?table=X-sectionU.L.1>Figure 5: 1D Cross-section Limits</a> <li><a href=?table=X-sectionU.L.2>Auxiliary Figure 3: 2D Cross-section Limits</a> </ul> <b>2D CL limits:</b><ul> <li><a href=?table=Exclusioncontour1>Figure 6: Expected Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour2>Figure 6: $+1\sigma$ Variation for Expected Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour3>Figure 6: $-1\sigma$ Variation for Expected Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour4>Figure 6: Observed Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour5>Figure 6: $+1\sigma$ Variation for Observed Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> <li><a href=?table=Exclusioncontour6>Figure 6: $-1\sigma$ Variation for Observed Limit on $\mathrm{BF}(\tilde{\chi}_1^0\rightarrow h\tilde{G})$</a> </ul> <b>2D Acceptance and Efficiency maps:</b><ul> <li><a href=?table=Acceptance1>Auxiliary Figure 4a: Acceptances SR1h</a> <li><a href=?table=Acceptance2>Auxiliary Figure 4b: Acceptances SR1Z</a> <li><a href=?table=Acceptance3>Auxiliary Figure 4c: Acceptances SR2</a> <li><a href=?table=Efficiency1>Auxiliary Figure 5a: Efficiencies SR1h</a> <li><a href=?table=Efficiency2>Auxiliary Figure 5b: Efficiencies SR1Z</a> <li><a href=?table=Efficiency3>Auxiliary Figure 5c: Efficiencies SR2</a> </ul>
Distribution of the diphoton invariant mass in validation region VR1. The solid histograms are stacked to show the SM expectations after the 2×2D background estimation technique is applied. Background and signal predictions are normalised to the luminosity. The background category "h (other)" includes events originating from VBF, Vh, ggF, thq, thW and bb̄h, all subdominant in this signature. Statistical and systematic uncertainties are indicated by the shaded area. The lower panel of each plot shows the ratio of the data to the SM prediction for the respective bin. The first and last bins include the underflows and overflows respectively.
Distribution of the missing transverse momentum in validation region VR1. The solid histograms are stacked to show the SM expectations after the 2×2D background estimation technique is applied. Background and signal predictions are normalised to the luminosity. The background category "h (other)" includes events originating from VBF, Vh, ggF, thq, thW and bb̄h, all subdominant in this signature. Statistical and systematic uncertainties are indicated by the shaded area. The lower panel of each plot shows the ratio of the data to the SM prediction for the respective bin. The first and last bins include the underflows and overflows respectively.
Inclusive and differential cross-sections are measured at particle level for the associated production of a top quark pair and a photon ($t\bar{t}\gamma$). The analysis is performed using an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at a centre-of-mass energy of 13 TeV collected by the ATLAS detector. The measurements are performed in the single-lepton and dilepton top quark pair decay channels focusing on $t\bar{t}\gamma$ topologies where the photon is radiated from an initial-state parton or one of the top quarks. The absolute and normalised differential cross-sections are measured for several variables characterising the photon, lepton and jet kinematics as well as the angular separation between those objects. The observables are found to be in good agreement with the Monte Carlo predictions. The photon transverse momentum differential distribution is used to set limits on effective field theory parameters related to the electroweak dipole moments of the top quark. The combined limits using the photon and the $Z$ boson transverse momentum measured in $t\bar{t}$ production in associations with a $Z$ boson are also set.
All the entries of this HEP data record are listed. Figure and Table numbers are the same as in the paper.
Measured $t\bar{t}\gamma$ production fiducial inclusive cross-sections in both decay channels and in the combination.
Summary of the impact of the systematic uncertainties on the $t\bar{t}\gamma$ production fiducial inclusive cross-section in the single-lepton and dilepton channels and their combination grouped into different categories. The quoted relative uncertainties are obtained by repeating the fit, fixing a set of nuisance parameters of the sources corresponding to each category to their post-fit values, and subtracting in quadrature the resulting uncertainty from the total uncertainty of the nominal fit. The total uncertainty is different from the sum in quadrature of the components due to correlations among nuisance parameters.
A search is performed for localized excesses in the low-mass dijet invariant mass distribution, targeting a hypothetical new particle decaying into two jets and produced in association with either a high transverse momentum photon or a jet. The search uses the full Run 2 data sample from LHC proton-proton collisions collected by the ATLAS experiment at a center-of-mass energy of 13 TeV during 2015-2018. Two variants of the search are presented for each type of initial-state radiation: one that makes no jet flavor requirements and one that requires both of the jets to have been identified as containing $b$-hadrons. No excess is observed relative to the Standard Model prediction, and the data are used to set upper limits on the production cross-section for a benchmark $Z'$ model and, separately, for generic, beyond the Standard Model scenarios which might produce a Gaussian-shaped contribution to dijet invariant mass distributions. The results extend the current constraints on dijet resonances to the mass range between 200 and 650 GeV.
Dijet invariant mass distributions data compared to the fitted background estimates for the $\gamma j j$ channel. The distributions are shown here with the $m_{jj}$ resolution binning.
Dijet invariant mass distributions data compared to the fitted background estimates for the $\gamma b b$ channel. The distributions are shown here with the $m_{jj}$ resolution binning.
Dijet invariant mass distributions data compared to the fitted background estimates for the $j j j$ channel. The distributions are shown here with the $m_{jj}$ resolution binning.
A search for charged-lepton-flavour violating $\mu\tau qt$ ($q=u,c$) interactions is presented, considering both top-quark production and decay. The data analysed correspond to 140 $\textrm{fb}^{-1}$ of proton-proton collisions at a centre-of-mass energy of $\sqrt{s}= $13 TeV recorded with the ATLAS detector at the Large Hadron Collider. The analysis targets events containing two muons with the same electric charge, a hadronically decaying $\tau$-lepton and at least one jet, with exactly one $b$-tagged jet, produced by a $\mu\tau qt$ interaction. Agreement with the Standard Model expectation within $1.6\sigma$ is observed, and limits are set at the 95% CL on the charged-lepton-flavour violation branching ratio of $\mathcal{B}(t \to \mu\tau q) < 8.7 \times 10^{-7}$. An Effective Field Theory interpretation is performed yielding 95% CL limits on Wilson coefficients, dependent on the flavour of the associated light quark and the Lorentz structure of the coupling. These range from $|c_{\mathsf{lequ}}^{3(2313)}| / \Lambda^{2} < 0.10\textrm{ TeV}^{-2}$ for $\mu\tau ut$ to $|c_{\mathsf{ lequ}}^{1(2323)}| / \Lambda^{2} < 1.8\textrm{ TeV}^{-2}$ for $\mu\tau ct$. An additional interpretation is performed for scalar leptoquark production inducing charged lepton flavour violation, with fixed inter-generational couplings. Upper limits on leptoquark coupling strengths are set at the 95% CL, ranging from $\lambda^{\textrm{LQ}} = $1.3 to $\lambda^{\textrm{LQ}} = $3.7 for leptoquark masses between 0.5 and 2.0 TeV.
Observed event yields in $\textrm{CR}t\bar{t}\mu$ compared with pre-fit expectations from Monte Carlo simulations, as a function of the scalar sum of lepton and jet transverse momenta, $H_{\mathrm{T}}$. The last bin includes overflow events. `Signal (prod.)' and `Signal (dec.)' refer to the single-top-quark production and top-quark pair decay signal contributions, respectively. The pre-fit signal yield represents all Wilson coefficients set to 0.1 simultaneously for a new physics scale of $\Lambda=1$ TeV.
Observed event yields in $\textrm{CR}t\bar{t}\mu$ compared with post-fit expectations from Monte Carlo simulations, as a function of the scalar sum of lepton and jet transverse momenta, $H_{\mathrm{T}}$. The last bin includes overflow events. `Signal (prod.)' and `Signal (dec.)' refer to the single-top-quark production and top-quark pair decay signal contributions, respectively.
Observed event yields in $\textrm{SR}$ compared with pre-fit expectations from Monte Carlo simulations, as a function of the scalar sum of lepton and jet transverse momenta, $H_{\mathrm{T}}$. The last bin includes overflow events. `Signal (prod.)' and `Signal (dec.)' refer to the single-top-quark production and top-quark pair decay signal contributions, respectively. The pre-fit signal yield represents all Wilson coefficients set to 0.1 simultaneously for a new physics scale of $\Lambda=1$ TeV.
A measurement of the production of $W$ bosons with opposite electric charges in association with two jets is presented based on 140 fb$^{-1}$ of data collected by the ATLAS detector in proton-proton collisions at $\sqrt{s}=13$ TeV. The analysis is sensitive to the scattering of $W$ bosons, which is of particular interest in the ATLAS physics programme as it can be used to probe the electroweak symmetry breaking mechanism of the Standard Model. This signal is observed with a significance of 7.1 standard deviations above the background expectation, while 6.2 standard deviations were expected. The measured cross-section is determined in a signal-enriched fiducial volume and is found to be $2.7\pm0.5$ fb, which is consistent with the theoretical prediction of $2.20^{+0.14}_{-0.13}$ fb.
Measurement of the signal strength $\mu=\mu(EWK\;W^+ W^- jj)$ from the likelihood fit described in Section 8 together with the normalisations of the backgrounds originating from the top quark and strong $W^+ W^- jj$ events.
Measurement of the measured and predicted signal cross-section.
Measurements of inclusive, differential cross-sections for the production of events with missing transverse momentum in association with jets in proton-proton collisions at $\sqrt{s}=13~$TeV are presented. The measurements are made with the ATLAS detector using an integrated luminosity of $140~$fb$^{-1}$ and include measurements of dijet distributions in a region in which vector-boson fusion processes are enhanced. They are unfolded to correct for detector resolution and efficiency within the fiducial acceptance, and are designed to allow robust comparisons with a wide range of theoretical predictions. A measurement of differential cross sections for the $Z~\to \nu\nu$ process is made. The measurements are generally well-described by Standard Model predictions except for the dijet invariant mass distribution. Auxiliary measurements of the hadronic system recoiling against isolated leptons, and photons, are also made in the same phase space. Ratios between the measured distributions are then derived, to take advantage of cancellations in modelling effects and some of the major systematic uncertainties. These measurements are sensitive to new phenomena, and provide a mechanism to easily set constraints on phenomenological models. To illustrate the robustness of the approach, these ratios are compared with two common Dark Matter models, where the constraints derived from the measurement are comparable to those set by dedicated detector-level searches.
The measured $p_\text{T}^\text{miss}$ differential cross-sections in the $p_\text{T}^\text{miss}+\text{jets}$ region of the incluse jet phase space, compared with the SM predictions. The middle panels show the ratios of the predictions to the data, along with their uncertainties, while the lower panels show the relative contributions from different SM processes relative to the total MEPS@NLO prediction. Note that individually numbered PDF components ('dK_PDF_') in the uncertainty breakdown correspond to NNPDF Hessian eigenvectors. Uncertainty components labeled 'VV_dK' include Vjj processes.
The measured $p_\text{T}^\text{recoil}$ differential cross-sections in the $1\mu+\text{jets}$ region of the incluse jet phase space, compared with the SM predictions. The middle panels show the ratios of the predictions to the data, along with their uncertainties, while the lower panels show the relative contributions from different SM processes relative to the total MEPS@NLO prediction. Note that individually numbered PDF components ('dK_PDF_') in the uncertainty breakdown correspond to NNPDF Hessian eigenvectors. Uncertainty components labeled 'VV_dK' include Vjj processes.
The measured $p_\text{T}^\text{recoil}$ differential cross-sections in the $1e+\text{jets}$ region of the incluse jet phase space, compared with the SM predictions. The middle panels show the ratios of the predictions to the data, along with their uncertainties, while the lower panels show the relative contributions from different SM processes relative to the total MEPS@NLO prediction. Note that individually numbered PDF components ('dK_PDF_') in the uncertainty breakdown correspond to NNPDF Hessian eigenvectors. Uncertainty components labeled 'VV_dK' include Vjj processes.
The production of single top quarks and top antiquarks via the $t$-channel exchange of a virtual $W$ boson is measured in proton-proton collisions at a centre-of-mass energy of 13 TeV at the LHC using $140\,\mathrm{fb^{-1}}$ of ATLAS data. The total cross-sections are determined to be $σ(tq)=137^{+8}_{-8}\,\mathrm{pb}$ and $σ(\bar{t}q)=84^{+6}_{-5}\,\mathrm{pb}$ for top-quark and top-antiquark production, respectively. The combined cross-section is found to be $σ(tq+\bar{t}q)=221^{+13}_{-13}\,\mathrm{pb}$ and the cross-section ratio is $R_{t}=σ(tq)/σ(\bar{t}q)=1.636^{+0.036}_{-0.034}$. The predictions at next-to-next-to-leading-order in quantum chromodynamics are in good agreement with these measurements. The predicted value of $R_{t}$ using different sets of parton distribution functions is compared with the measured value, demonstrating the potential to further constrain the functions when using this result in global fits. The measured cross-sections are interpreted in an effective field theory approach, setting limits at the 95% confidence level on the strength of a four-quark operator and an operator coupling the third quark generation to the Higgs boson doublet: $-0.37 < C_{Qq}^{3,1}/Λ^2 < 0.06$ and $-0.87 < C_{ϕQ}^{3}/Λ^2 < 1.42$. The constraint $|V_{tb}|>0.95$ at the 95% confidence level is derived from the measured value of $σ(tq+\bar{t}q)$. In a more general approach, pairs of CKM matrix elements involving top quarks are simultaneously constrained, leading to confidence contours in the corresponding two-dimensional parameter spaces.
The 17 variables used for the training of the NN ordered by their discriminating power. The jet that is not \(b\)-tagged is referred to as the untagged jet. The charged lepton is denoted \(\ell\). The sphericity tensor \(S^{\alpha\beta}\) used to define the sphericity \(S\) is formed with the three-momenta \(\vec{p}_i\) of the reconstructed objects, namely the jets, the charged lepton and the reconstructed neutrino. The tensor is given by \(S^{\alpha\beta}=\frac{\sum_i p_i^\alpha p_i^\beta}{\sum_i |\vec{p}_i|^2}\) where \(\alpha\) and \(\beta\) correspond to the spatial components $x$, $y$ and $z$.
The impact of different groups of systematic uncertainties on the \(\sigma(tq)\) , \(\sigma(\bar t q)\), \(\sigma(tq + \bar t q)\) and \(R_t\), given in %.
The impact of the eight most important systematic uncertainties on the \(\sigma(tq)\) , \(\sigma(\bar t q)\) and \(\sigma(tq + \bar t q)\), given in %. The sequence of the uncertainties is given by the impact on \(\sigma(tq + \bar t q)\)
The ratio of branching ratios of the $W$ boson to muons and electrons, $R^{\mu/e}_W=B(W\rightarrow \mu\nu)/B(W\rightarrow e\nu)$, has been measured using 140 fb$^{-1}$ of $pp$ collision data at $\sqrt{s}=13$ TeV collected with the ATLAS detector at the LHC, probing the universality of lepton couplings. The ratio is obtained from measurements of the $t\bar{t}$ production cross-section in the $ee$, $e\mu$ and $\mu\mu$ dilepton final states. To reduce systematic uncertainties, it is normalised by the square root of the corresponding ratio $R^{\mu\mu/ee}_Z$ for the $Z$ boson measured in inclusive $Z\rightarrow ee$ and $Z\rightarrow\mu\mu$ events. By using the precise value of $R^{\mu\mu/ee}_Z$ determined from $e^+e^-$ colliders, the ratio $R^{\mu/e}_W$ is determined to be $R^{\mu/e}_W = 0.9995 \pm 0.0022 \pm 0.0036 \pm 0.0014$. The three uncertainties correspond to data statistics, experimental systematics and the external measurement of $R^{\mu\mu/ee}_Z$, giving a total uncertainty of 0.0045, and confirming the Standard Model assumption of lepton flavour universality in $W$-boson decays at the 0.5% level.
The measurement of the ratio of the rate of decay of W bosons to muons and electrons, $R(\mu/e)=B(W\rightarrow\mu\nu)/B(W\rightarrow e\nu)$.
Searches for the exclusive decays of the Higgs boson into $D^*\gamma$ and of the $Z$ boson into $D^0\gamma$ and $K^0_s\gamma$ can probe flavour-violating Higgs and $Z$ boson couplings to light quarks. Searches for these decays are performed with a $pp$ collision data sample corresponding to an integrated luminosity of $136.3$ fb$^{-1}$ collected at $\sqrt{s}=13$ TeV between 2016-2018 with the ATLAS detector at the CERN Large Hadron Collider. In the $D^*\gamma$ and $D^0\gamma$ channels, the observed (expected) 95$\%$ confidence-level upper limits on the respective branching fractions are ${\cal B}(H\rightarrow D^*\gamma)< 1.0 (1.2)\times 10^{-3}$, ${\cal B}(Z\rightarrow D^0\gamma)< 4.0 (3.4)\times 10^{-6}$, while the corresponding results in the $K^0_s\gamma$ channel are ${\cal B}(Z\rightarrow K^0_s\gamma)< 3.1 (3.0)\times 10^{-6}$.
Numbers of observed and expected background events for the $m_{\mathcal{M}\gamma}$ ranges of interest. Each expected background and the corresponding uncertainty is obtained by integrating the total pdf after a background-only fit to the data, where the uncertainty does not take into account statistical fluctuations in each mass range. Expected Higgs and $Z$ boson signal contributions, with their corresponding total systematic uncertainty, are shown for reference branching fractions of $10^{-3}$ and $10^{-6}$, respectively. Entries are marked with a dash when there is no signal of that type in the specified range.
Observed and expected (with the corresponding $\pm1\sigma$ intervals) 95% CL upper limits on the branching fractions for $H\rightarrow D^*\gamma$, $Z\rightarrow D^0\gamma$ and $Z\rightarrow K^0_s\gamma$. Standard Model production of the Higgs boson is assumed. The corresponding upper limits on the production cross-section times branching fraction $\sigma\times\mathcal{B}$ are also shown.
This Letter presents the first study of the energy-dependence of diboson polarization fractions in $WZ \rightarrow \ell\nu \ell'\ell'~(\ell, \ell'=e, \mu)$ production. The data set used corresponds to an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at a center-of-mass energy of 13 TeV recorded by the ATLAS detector. Two fiducial regions with an enhanced presence of events featuring two longitudinally-polarized bosons are defined. A non-zero fraction of events with two longitudinally-polarized bosons is measured with an observed significance of 5.2 standard deviations in the region with $100<p_T^Z\leq200$ GeV and 1.6 standard deviations in the region with $p_T^Z>200$ GeV, where $p_T^Z$ is the transverse momentum of the $Z$ boson. This Letter also reports the first study of the Radiation Amplitude Zero effect. Events with two transversely-polarized bosons are analyzed for the $\Delta Y(\ell_W Z)$ and $\Delta Y(WZ)$ distributions defined respectively as the rapidity difference between the lepton from the $W$ boson decay and the $Z$ boson and the rapidity difference between the $W$ boson and the $Z$ boson. Significant suppression of events near zero is observed in both distributions. Unfolded $\Delta Y(\ell_W Z)$ and $\Delta Y(WZ)$ distributions are also measured and compared to theoretical predictions.
Polarization fractions in the region with $100<p_T^Z\leq200$ GeV using three unconstrained parameters.
Polarization fractions in the region with $p_T^Z>200$ GeV using three unconstrained parameters.
Fraction of events where both bosons are longitudinally polarized in the region with $100<p_T^Z\leq200$ GeV using two unconstrained parameters.
A search for high-mass resonances decaying into a $\tau$-lepton and a neutrino using proton-proton collisions at a center-of-mass energy of $\sqrt{s}=13$ TeV is presented. The full Run 2 data sample corresponding to an integrated luminosity of 139 fb$^{-1}$ recorded by the ATLAS experiment in the years 2015-2018 is analyzed. The $\tau$-lepton is reconstructed in its hadronic decay modes and the total transverse momentum carried out by neutrinos is inferred from the reconstructed missing transverse momentum. The search for new physics is performed on the transverse mass between the $\tau$-lepton and the missing transverse momentum. No excess of events above the Standard Model expectation is observed and upper exclusion limits are set on the $W^\prime\to \tau \nu$ production cross-section. Heavy $W^\prime$ vector bosons with masses up to 5.0 TeV are excluded at 95% confidence level, assuming that they have the same couplings as the Standard Model $W$ boson. For non-universal couplings, $W^\prime$ bosons are excluded for masses less than 3.5-5.0 TeV, depending on the model parameters. In addition, model-independent limits on the visible cross-section times branching ratio are determined as a function of the lower threshold on the transverse mass of the $\tau$-lepton and missing transverse momentum.
Observed and predicted $m_{\rm T}$ distributions including SSM and NU (cot$\theta$ = 5.5) $W^{\prime}$ signals with masses of 4 TeV. Please note that in the paper figure the bin content is divided by the bin width, but this is not done in the HepData table.
Observed and expected 95% CL upper limits on cross section times $\tau\nu$ branching fraction for $W^{\prime}_{\rm SSM}$.
Regions of the non-universal parameter space excluded at 95% CL.
A search for a new $Z'$ gauge boson predicted by $L_{\mu}-L_{\tau}$ models, based on charged-current Drell-Yan production, $pp \rightarrow W^{\pm(*)} \rightarrow Z' \mu^{\pm} \nu \rightarrow \mu^{\pm}\mu^{\mp}\mu^{\pm}\nu$, is presented. The data sample used corresponds to an integrated luminosity of 140 fb$^{-1}$ of proton-proton collisions at $\sqrt{s} = 13$ TeV recorded by the ATLAS detector at the Large Hadron Collider. The search examines a final state of $3\mu$ plus large missing transverse momentum. Upper limits are set on the $Z'$ production cross-section times branching ratio in the mass range of 5-81 GeV. After combining with the previous $Z'$ search using the neutral-current Drell-Yan production with a $4\mu$ final state, the most stringent exclusion limits to date are achieved in the parameter space of the $Z'$ coupling strength and mass.
Observed and expected upper limits at 95% CL on the production cross-section times branching fraction of the process $pp\to W\to Z^{\prime}$ $\mu \nu \to \mu \mu \mu \nu$ as a function of $m_{Z^{\prime}}$.
Observed and expected upper limits at 95% CL on the coupling parameter $g_{Z^{\prime}}$ as a function of $m_{Z^{\prime}}$ from the statistical combination of the $3\mu$ and $4\mu$ channels.
Exclusion contour compared to the limits from the Neutrino Trident and the $B_{S}$ mixing experimental results.